Rhubarb Upside-Down Crumb Cake
This pretty rhubarb cake with its sweet, buttery crust would be a welcome addition to any brunch table.
For the Crumb Crust
- 1/2 cup (1 stick) unsalted butter, melted
- 1 cup all-purpose flour
- 1/2 cup sugar
- 1/2 teaspoon coarse salt
For the Cake
- 1 1/2 cups (3 sticks) unsalted butter, room temperature, plus more for pan
- 1 pound rhubarb, trimmed and cut on a very sharp diagonal about 1/4 inch thick
- 1 3/4 cups sugar
- 1 1/2 cups all-purpose flour
- 1 1/2 teaspoons baking powder
- 1 1/2 teaspoons coarse salt
- 2 large eggs
- 1 teaspoon finely grated lemon zest
- 1 tablespoon freshly squeezed lemon juice
- 1 cup sour cream
Preheat oven to 350 degrees.
Make the topping: Stir together butter, flour, sugar, and 1/2 teaspoon salt until moist and crumbly.
Make the cake: Butter a 9-inch round cake pan (3 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 eggs, 1 at a time, until incorporated, scraping down sides of bowl. Beat in zest and juice. 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.