This is the season for rhubarb; some of you may find rhubarb in your shares. Probably the most important fact about rhubarb is that the leaves are POISONOUS!
Rhubarb can be kept up to 5days in a plastic bag in your refrigerator.
Rhubarb Upside-Down Cake
For the Topping: (the topping will be on the bottom when the cake is inverted.)
4 tablespoons unsalted butter, melted
1/2 cup all-purpose flour
1/4 cup sugar
For the Cake:
1 1/2 sticks unsalted butter, room temperature, plus more for buttering pan
1 pound rhubarb, trimmed and cut on a very sharp diagonal about 1/2 inch thick
1 3/4 cups sugar
1 1/2 cups all-purpose flour
1 1/2 teaspoons baking powder
1/2 teaspoon finely grated orange zest plus 1 tablespoon fresh orange juice
2 large eggs
1 cup sour cream
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.
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 freshly squeezed lemon juice instead of orange zest and juice in the cake.