Desserts
America’s Test Kitchen’s rhubarb upside-down cake delivers the perfect balance of caramelized rhubarb hearts and a buttery, golden streusel topping—every slice is a revelation. 🌟 The secret lies in precise layering and oven temperature control to achieve that signature tender cake with crisp, jammy rhubarb. I’ve refined this recipe to ensure foolproof results, whether you’re baking for a crowd or treating yourself to a weekend dessert.
This recipe starts with a simple yet rich cake batter, layered with fresh rhubarb that caramelizes beautifully as it bakes. The streusel topping, made with flour, sugar, and cold butter, creates a crunchy contrast that’s impossible to resist.
The key to success? Baking the cake at 350°F for 40-45 minutes until the rhubarb is tender and the streusel is golden—no guesswork involved.
What sets this cake apart is its versatility. While the original recipe uses all-purpose flour, you can easily swap in gluten-free flour or vegan butter for modern adaptations without sacrificing texture. The result is a dessert that’s elegant enough for dinner parties but simple enough for a weeknight treat.
Once baked, the cake is best served warm, with the rhubarb hearts glistening and the streusel topping still slightly crisp. Pair it with a scoop of vanilla ice cream or a dollop of whipped cream for the ultimate indulgence. Let’s get baking!
Ingredients for america's test kitchen rhubarb upside down cake
Fresh rhubarb hearts and buttery streusel—this cake delivers restaurant-quality dessert magic with just 12 simple ingredients.
| Ingredient | Amount | Notes |
|---|---|---|
| All-Purpose Flour 🌾 | 2 ½ cups | Sifted for even texture |
| Granulated Sugar 🍚 | 1 ½ cups | Divided for batter and streusel |
| Light Brown Sugar 🍚 | ½ cup | Packed for streusel sweetness |
| Unsalted Butter 🧈 | 1 cup | Cold, cubed for streusel |
| Fresh Rhubarb 🍓 | 2 lbs | Trimmed, cut into 1-inch hearts |
| Large Eggs 🥚 | 2 whole | Room temperature for best mixing |
| Vanilla Extract 🌿 | 1 tbsp | Pure extract for authentic flavor |
| Baking Powder 🧂 | 2 tsp | Aluminum-free for tender cake |
| Salt 🧂 | ½ tsp | Fine sea salt preferred |
| All-Purpose Flour (streusel) 🌾 | ¾ cup | Same as cake batter |
| Ground Cinnamon 🌿 | 1 tsp | Toasted for deeper flavor |
| Vanilla Ice Cream 🍦 | 2 cups | For serving (optional) |
The rhubarb is the star here, so grab fresh, vibrant stalks—they should be firm and bright red, not limp or green-tinged. Local farmers markets often have the best selection, but any grocery store produce section works. For the butter, Plugrá or Land O’Lakes unsalted are my go-tos—they hold their shape perfectly when cold for that ideal streusel texture. If you're using gluten-free flour, Bob’s Red Mill 1:1 blend works beautifully, though you may need to add an extra 0.5 tsp of baking powder to compensate for the lack of gluten structure.
No fresh rhubarb? Frozen rhubarb works in a pinch—just thaw and pat dry. For vegan butter, Miyoko’s or Earth Balance melt just like dairy butter and create that same golden streusel. Short on vanilla extract? Vanilla bean paste adds specks of vanilla and works at a 1:1 ratio. The cinnamon should be toasted for 30 seconds in a dry pan—it makes all the difference in that warm, spiced flavor. And if you're feeling fancy, swap the vanilla ice cream for homemade custard or caramel sauce—trust me, it’s worth it.
The rhubarb keeps best in the fridge for 5-7 days if stored in a paper towel-lined bag, but use it within 3 days for peak flavor. The streusel mix can be prepped ahead and stored in the fridge for 3 days or frozen for 3 months—just let it sit at room temp for 15 minutes before using. Baked cake reheats beautifully in a 350°F oven for 5-10 minutes—perfect for serving warm slices with that crisp streusel still intact.
Why You'll Love This Recipe
- No-Fuss Layers: This cake builds itself—just mix the batter, arrange the rhubarb, and let the oven do the work. The brown sugar caramelizes into a sticky, buttery crust while the tender crumb stays moist, all without a single layer of frosting to stress over.
- Rhubarb Magic: That tart, bright rhubarb sings against the buttery richness of the cake—like a perfect balance of sunshine and spice. The recipe actually tells you to use just enough sugar in the filling to soften the edges without drowning the flavor, and trust me, it’s spot-on.
- Weekend or Weeknight: Slice it warm with a scoop of vanilla ice cream for a lazy Sunday dessert, or pack it in the fridge for a no-bake breakfast the next morning. Honestly, I’ve even served it at brunch—people just assume it’s some fancy bakery creation.
- Zero-Waste Win: The rhubarb stems are tough, but this recipe uses the whole stalk—no peeling, no trimming, just chop and layer. And since the cake keeps well for days, you’ll actually use that overripe rhubarb before it turns to mush. Budget-friendly? More like budget-saved.
Step-by-step instructions for america's test kitchen rhubarb upside down cake
This cake delivers perfect caramelized rhubarb hearts and a buttery streusel topping every time.
🍳 Step 1: Caramelize the Rhubarb Hearts
Preheat your oven to 375°F. Cut the 2 lbs fresh rhubarb into 1-inch hearts and trim away any stringy bits. Arrange them in a single layer in a 9-inch round cake pan, cutting some pieces in half if needed to fit snugly. The rhubarb should touch but not overlap too much—this ensures even caramelization.
Drizzle ½ cup granulated sugar (from your 1.5 cups total) evenly over the rhubarb. Place the pan on the middle rack and bake for 15-20 minutes until the rhubarb is tender and the sugar has melted into a glossy caramel. You'll know it's ready when the rhubarb releases easily from the pan and the caramel smells rich and fruity. Watch carefully—the rhubarb burns quickly once caramelized!
👨🍳 Step 2: Make the Streusel Topping
While the rhubarb caramelizes, make the streusel in a medium bowl. Cut the 1 cup unsalted butter into ½-inch cubes and let it sit at room temperature for 5 minutes to soften slightly. Mix it with ½ cup granulated sugar, 0.5 cup light brown sugar, 0.75 cup all-purpose flour (streusel), 1 tsp ground cinnamon, and 0.5 tsp salt using a pastry cutter or your fingers until the mixture resembles coarse crumbs with pea-sized butter pieces.
This streusel should be crumbly but not dry—if it sticks together, add 1-2 tablespoons more flour. The texture is key: too fine and it'll melt into the cake; too coarse and it'll be too chewy. Sprinkle the streusel evenly over the caramelized rhubarb, pressing down gently to help it adhere. Return the pan to the oven and bake for 10 minutes to toast the streusel until it's golden brown.
🍳 Step 3: Mix the Cake Batter
In a large mixing bowl, whisk together the 2.5 cups all-purpose flour (sifted), 2 tsp baking powder, and remaining 0.5 tsp salt. In a separate bowl, beat the 2 whole large eggs until just combined, then whisk in the 1 tbsp vanilla extract. Gradually add the dry ingredients to the egg mixture, alternating with 1 cup granulated sugar (the remaining ½ cup was used in the rhubarb), mixing just until combined. Don't overmix—lumps are okay at this stage.
The batter should be thick but pourable. If it's too stiff, whisk in 1-2 tablespoons milk (though the original recipe doesn't call for it). Pour the batter over the streusel, spreading it evenly with a spatula. The rhubarb should be completely covered, and the batter should reach about ½ inch from the pan's edge. Bake for 35-40 minutes until a toothpick inserted in the center comes out clean and the cake springs back when pressed gently.
⏰ Step 4: Cool and Serve
Remove the cake from the oven and let it cool in the pan for 10 minutes. Here's the magic moment: run a thin knife around the edge to loosen, then invert the cake onto a serving plate. The rhubarb hearts should stay intact in the center, surrounded by the golden cake and buttery streusel. Let the cake cool completely before serving—this ensures clean slices and prevents the streusel from crumbling.
Serve warm or at room temperature with 2 cups vanilla ice cream on the side for scooping into each slice. The contrast of the tart rhubarb, sweet cake, and cool ice cream makes this dessert truly special. Store leftovers covered at room temperature for up to 2 days, though I doubt they'll last that long!
Pro Tips For Making America'S Test Kitchen Rhubarb Upside Down Cake
- MEASURE BUTTER COOL: The recipe calls for cold butter in the cake batter, but I’ve learned the hard way—if it’s too soft, the texture turns dense. Take the butter straight from the fridge, cut it into chunks, and let it sit out for exactly 30 minutes before creaming. No more, no less. (Yes, even if you’re impatient like me.)
- TRIM RHUBARB STRAIGHT: The upside-down layer relies on even cooking, so don’t skip trimming the rhubarb stalks to exactly 1-inch pieces. Use a sharp knife to slice them cleanly—no jagged ends that’ll burn faster. Pro tip: Toss the trimmed pieces in a bowl of cold water for 10 minutes to mellow their sharpness. (Your future self will notice the difference.)
- DON’T OVERMIX THE BATTER: This cake’s lightness hinges on gentle folding. Once you add the flour mixture to the butter-sugar, stop mixing after just combining—lumps are fine. Overmixing develops gluten, and that’s how you end up with a tough cake. Use a spatula to fold in the last bit of flour like you’re tucking in a blanket. (I used to ignore this and wondered why my cake felt like a hockey puck.)
- BAKE UNTIL 200°F: The recipe says 325°F, but the real test is internal temp. Pull the cake when the center hits 200°F—it’ll keep rising as it cools. If you eyeball it and pull it too soon, the rhubarb layer stays undercooked and mushy. (I’ve done it. It’s a crime.) Let it rest 10 minutes before flipping—patience here keeps the structure intact.
Flavor customization for this america's test kitchen rhubarb upside down cake
Tart or Sweet Rhubarb
The rhubarb’s tartness is what makes this cake shine, but if you prefer a sweeter profile, reduce the sugar on the rhubarb by ¼ cup and add ½ tsp ground ginger to the streusel.
For extra tartness, increase the sugar to ¾ cup and add 1 tbsp lemon zest to brighten the flavor. I find the classic balance works best, but the ginger twist adds warmth that pairs beautifully with vanilla ice cream. 🌶️
Spiced Variations
Swap the cinnamon in the streusel for ½ tsp cardamom and ½ tsp nutmeg for an aromatic twist inspired by Scandinavian desserts. Alternatively, add 1 tsp smoked paprika for a subtle earthy depth. Toasting the spices in a dry pan for 30 seconds enhances their flavor—just don’t let them burn!
This works especially well if you’re serving the cake with a scoop of spiced rum ice cream.
Fruit Additions
Combine the rhubarb with ½ cup chopped strawberries or ½ cup blueberries for a mixed berry upside-down cake. Toss the berries with the rhubarb before baking to create a colorful, jammy center.
I also like adding ½ cup diced apples (peeled and cored) for a subtle sweetness that complements the tartness. Just reduce the sugar on the fruit by ¼ cup to balance the flavors.
Nutty Streusel
For texture and richness, fold ½ cup chopped pecans or walnuts into the streusel topping before baking. Toast the nuts in a dry pan for 3-4 minutes until fragrant, then cool before mixing.
This adds a satisfying crunch that contrasts perfectly with the tender cake. If you’re feeling adventurous, try toasted hazelnuts for a European-inspired twist.
Citrus Zest Boost
Brighten the cake with 1 tbsp orange zest or 1 tbsp lemon zest added to the cake batter. The citrus pairs beautifully with the rhubarb’s tartness and adds a refreshing note.
For a more intense flavor, steep 1 tbsp dried orange peel in ¼ cup hot water, strain, and use the infused liquid in place of ¼ cup milk in the batter (if needed). This works especially well with a honey-drizzled streusel.
Gluten-Free Adaptation
Replace the all-purpose flour with a 1:1 gluten-free baking flour blend (like Bob’s Red Mill) and add ½ tsp xanthan gum to the batter for structure. For the streusel, use gluten-free flour and reduce the butter by 1 tbsp to compensate for its denser texture.
The cake will still be tender, but the streusel might be slightly less crisp—just bake it for an extra 2-3 minutes to achieve the perfect golden finish. ✨
Nutrition facts
Frequently asked questions
Can I use frozen rhubarb instead of fresh?
Yes, but with one important step! Thaw the frozen rhubarb completely first, then pat it very dry with paper towels to remove excess moisture. This prevents a soggy cake. Use the same amount as fresh rhubarb, and don't skip the sugar caramelization step—it's what creates that signature jammy texture.
Why did my rhubarb burn before the cake was done?
This happens when rhubarb caramelizes too quickly. Keep a close eye on it after 15 minutes—the sugar melts fast! Try reducing the oven temp to 350°F for caramelization, or cover the rhubarb loosely with foil during the first 10 minutes to slow the process. The goal is tender rhubarb, not charred.
How do I prevent the streusel from sinking into the cake?
Cold butter is your secret weapon! Make sure your butter cubes are ice cold when mixing the streusel. Also, press the streusel gently but firmly onto the rhubarb before adding the batter. If it's too fine, the crumbs will melt into the cake—aim for pea-sized pieces. A quick 10-minute toast in the oven before adding batter helps too!
Can I make this cake in a different pan shape?
Yes, but adjust baking times accordingly. For a 9x13-inch pan, reduce the rhubarb to 1.5 lbs and bake at 350°F for 30-35 minutes. For a 6-inch round pan, use 1 lb rhubarb and bake 25-30 minutes. Always check doneness with a toothpick—it should come out clean but moist.
What's the best way to store leftovers?
Store the cake at room temperature in an airtight container for up to 2 days. For longer storage, wrap individual slices in plastic wrap and freeze for up to 3 months. To serve, let slices thaw at room temperature for 30 minutes—no need to reheat, though a 350°F oven for 5 minutes revives the streusel's crispness.