Louise Galen's upside-down cake has the classic version's gooey caramel but is less sweet because it's made with rhubarb and crème fraîche.
Prep and cook time: About 1 1/4 hours
1 cup granulated sugar
2 cups sliced rhubarb (1/2 in. thick)
1 teaspoon grated lemon peel
2 tablespoons lemon juice
1/2 cup plus 2 tablespoons butter
1/3 cup firmly packed brown sugar
2 tablespoons bourbon or orange juice
1/2 cup pecan halves
2 large eggs
1 1/2 teaspoons baking powder
1 teaspoon vanilla
1/4 teaspoon salt
1 carton (7 1/2 to 8 oz.) crème fraîche or sour cream
2 cups all-purpose flour
How to Make It
In a bowl, combine 1/4 cup granulated sugar, the rhubarb, lemon peel, and 1 tablespoon lemon juice.
In a 10-inch frying pan over medium heat, melt 2 tablespoons butter; add brown sugar, bourbon, and remaining 1 tablespoon lemon juice; stir often until caramel has thickened and is medium brown, 7 to 10 minutes. Spread in a buttered 9-inch round cake pan (with 2-in.-tall sides).
Arrange pecans over caramel. Scatter rhubarb mixture on top.
In a bowl, with a mixer on medium speed, beat remaining 1/2 cup butter and 3/4 cup granulated sugar until blended. Beat in eggs until smooth. Beat in baking powder, vanilla, and salt, half the crème fraîche, then half the flour; repeat with remaining crème fraîche and flour. Drop spoonfuls of batter over rhubarb; spread smooth.
Bake in a 350° oven until cake is golden on top and a toothpick inserted in center comes out clean, 40 to 50 minutes. Let cool on a rack 15 minutes.
Run a knife between cake and pan sides. Invert onto a plate. Serve warm.