America's Test Kitchen Rhubarb Upside Down Cake Recipe: Buttery Streusel Crown Over Tangy Fruit Layers

This America's Test Kitchen rhubarb upside down cake delivers a perfect balance of tangy fruit and buttery streusel in every bite. The secret lies in a precise baking technique that ensures a golden, crisp streusel crown while keeping the rhubarb layers tender and juicy.

I've perfected this recipe over countless trials, and it never fails to impress—whether you're serving it at a brunch spread or enjoying a slice as an afternoon treat.

The cake starts with a simple yet flavorful batter that forms the base, topped with a layer of fresh rhubarb arranged in a circular pattern. A thick, buttery streusel topping—made with flour, sugar, and cold butter—bakes into a caramelized crown that adds texture and richness.

The key to success is baking at the right temperature and timing, which ensures the rhubarb stays vibrant while the streusel develops its signature crispness.

What you'll end up with is a visually stunning dessert that's as beautiful as it is delicious. The golden streusel crown contrasts perfectly with the bright pink rhubarb layers, creating a striking presentation that's sure to impress.

Each slice offers a harmonious blend of tart rhubarb, sweet streusel, and a tender cake base—making it a crowd-pleaser for any occasion.

This recipe is adaptable for most dietary preferences, though traditional butter and all-purpose flour deliver the best results. For a lighter texture, you can reduce the sugar slightly, but the classic version remains foolproof and consistently delicious. Let's get baking!

Ingredients for america's test kitchen rhubarb upside down cake

Buttery streusel meets tart rhubarb in this foolproof upside down cake—just 13 ingredients, big flavor.

The rhubarb is non-negotiable here—look for bright pink stalks with crisp texture, not mushy or slimy. Local farmers markets usually have the freshest, but any grocery store produce section works. Trim the leafy ends and slice into even 1/4-inch pieces. For extra tartness, toss the rhubarb with the lemon juice right before arranging it in the pan. The butter? Crisco or Land O'Lakes both work, but keep it cold for that perfect streusel crunch. If you can't find old-fashioned oats, quick oats work in a pinch—just pulse them briefly in a food processor first.

No rhubarb? Substitute with tart apples or peaches, but reduce lemon juice to 1/2 tbsp. Short on brown sugar? White sugar plus 1/2 tsp molasses mimics the flavor. The milk can be swapped for almond or oat milk if needed, though the texture might be slightly denser. For a lighter cake, replace 1/2 cup flour with gluten-free 1:1 blend. The vanilla extract is crucial—imitation vanilla has no depth. If you're feeling fancy, add a pinch of cardamom to the streusel for a sophisticated twist.

This cake keeps beautifully—3 days at room temperature covered loosely, or 1 week refrigerated in an airtight container. For longer storage, slice and freeze portions for up to 3 months. The streusel crown gets crunchier as it sits, so I like to serve it at room temperature. If reheating, wrap a slice in foil and warm for 10-15 seconds to keep the streusel crisp. Leftovers? Toss them in a blender with ice cream for a quick upside down cake milkshake—trust me, it's genius.

Step-by-step instructions for america's test kitchen rhubarb upside down cake

Here's how to build this showstopper with a perfect balance of tangy rhubarb and buttery streusel crown.

Trim the ends from the 2.5 lbs rhubarb and cut each stalk into ½-inch thick slices. Spread them evenly in a 9-inch round cake pan, pressing down gently to create a single layer. This ensures even cooking and prevents a watery bottom.

In a small bowl, whisk together the 1 tbsp lemon juice with 2 tablespoons of the 1.5 cups granulated sugar. Pour this mixture evenly over the rhubarb slices. The acidity will help brighten the rhubarb's natural tartness while preventing it from turning mushy during baking.

In a medium bowl, combine the 0.5 cup brown sugar, 0.5 cup old-fashioned oats, and 1 tsp ground cinnamon. Cut in the 1 cup unsalted butter using a pastry cutter or your fingers until the mixture resembles coarse crumbs with pea-sized butter pieces. This texture creates that signature crunchy crown.

Sprinkle the streusel evenly over the rhubarb layer, pressing down lightly to help it stick. The butter will melt slightly during baking, binding everything together while creating that irresistible crunchy contrast against the tender cake.

In a large bowl, whisk together the 2.5 cups all-purpose flour, 2 tsp baking powder, and 0.5 tsp salt. In a separate bowl, beat the 2 whole eggs until smooth, then whisk in the 1 cup milk, remaining 1.25 cups granulated sugar, and 1 tsp vanilla extract.

Gradually add the dry ingredients to the wet mixture, stirring just until combined. The batter should be smooth but slightly thicker than typical cake batter—this helps create the perfect texture when baked upside down. Don't overmix or you'll develop gluten that makes the cake tough.

Pour the batter over the streusel-topped rhubarb, spreading it evenly to the edges of the pan. Tap the pan gently on the counter to release any air bubbles. Bake in a preheated 350°F oven for 55-60 minutes, until a toothpick inserted in the center comes out clean.

Here's the magic moment: when the cake is done, immediately invert it onto a serving plate. Let it cool completely before slicing—this prevents the layers from sliding apart. The rhubarb should be tender but not mushy, the cake moist but not dense, and that streusel crown should be perfectly crisp.

Essential equipment for great america's test kitchen rhubarb upside down cake

9-Inch Cake Pan

This recipe requires a 9-inch round cake pan with a 2-inch deep sides—I recommend a light-colored metal pan like Wilton's Perfect Results for even baking. The pan should be lightly greased with butter and floured to prevent sticking, especially around the rhubarb layer.

If you don't have a round pan, a square pan works but may affect the presentation. 🧑‍🍳

Mixing Bowls

Use three medium mixing bowls (8-12 cups capacity) for the batter, streusel, and rhubarb prep. I prefer stainless steel or glass bowls—they're non-reactive and easy to clean. For the streusel, a pastry cutter or your fingers works best for cutting cold butter into the dry ingredients.

A small whisk helps blend the wet ingredients smoothly. 🥣

Pastry Cutter

A pastry cutter (like OXO Good Grips) is essential for creating the perfect streusel texture—cutting cold butter into the dry ingredients until pea-sized pieces remain. If you don't have one, two forks or your fingers work in a pinch.

The goal is coarse crumbs with butter pockets that melt into a crispy crown during baking. Avoid food processors for this step—they'll overwork the mixture. ⚡

Measuring Tools

Precision matters in baking! Use a quart-sized liquid measuring cup for the milk and dry measuring cups (like Pyrex) for the flour and sugar. A microplane helps zest the rhubarb if you want extra brightness.

For the streusel, a small kitchen scale ensures accurate measurements—especially for the brown sugar and oats. I keep my tools on a magnetic strip for easy access. 📏

Oven Thermometer

Your oven's temperature can vary by 25°F or more—an oven thermometer (like Thermoworks Oven Thermometer) ensures your 350°F setting is accurate. Place it in the center rack while preheating.

If your oven runs hot, reduce the temperature to 325°F to prevent a dry cake or over-browned streusel. Test it before baking to avoid surprises. 🌡️

Cooling Rack

A wire cooling rack is a must for this upside-down cake—it prevents moisture buildup under the pan, which can make the cake soggy. After baking, invert the cake onto the rack immediately and let it cool completely (at least 1 hour) before slicing.

I use a large rack to hold the entire pan while it cools. 💨

Frequently asked questions