Food & Cooking Recipes Dessert & Treats Recipes Cake Recipes Rhubarb Upside-Down Cake 3.6 (501) Prep Time: 25 mins Total Time: 2 hrs 15 mins Servings: 10 Yield: 1 9-inch cake This cake has a crumb "topping" that actually ends up on the bottom. Each bite has a surprisingly crunchy texture. Directions Preheat oven to 350 degrees. Make the topping: Stir together butter, flour, sugar, and 1/4 teaspoon salt until moist and crumbly. Make the cake: Butter a 9-inch round cake pan (2 inches deep). Dot with 4 tablespoons butter (cut into pieces). Toss rhubarb with 3/4 cup sugar; let stand for 2 minutes. Toss again, and spread in pan. Whisk together flour, baking powder, and 1 1/2 teaspoons salt. Beat remaining stick butter and cup sugar with a mixer on medium speed until pale and fluffy. Beat in zest and juice. Beat in eggs, 1 at a time, until incorporated, scraping down sides of bowl. Beat in flour mixture in 3 additions, alternating with sour cream, until smooth. Spread evenly over rhubarb. Crumble topping evenly over batter. Bake until a toothpick inserted into the center comes out clean and top springs back when touched, about 1 hour. Let cool for 10 minutes. Run a knife around edge of cake, and invert onto a wire rack. Let cool completely. Cook's Notes Let the cake cool for 10 minutes before removing it from the pan. The rhubarb will be too hot to handle safely right after baking. But if the cake sits much longer, it may stick. Variations On "Martha Bakes," Martha doubled the amount of crumb topping and used 1 teaspoon finely grated lemon zest and 1 tablespoon fresh lemon juice instead of orange zest and juice in the cake.