TOPPING:
5 cups bla:ck plums or pluots, skins on and thinly sliced
3 tablespoons butter
1/2 cup sugar

CAKE:
1 1/2 cups plus 2 tablespoons all-purpose flour 
1 teaspoon baking powder
1 teaspoon baking soda
1/2 teaspoon salt
1 teaspoon ground ginger
1/4 teaspoon ground cardamom
6 tablespoons butter, softened
3/4 cup sugar
1 teaspoon vanilla
2 eggs
3/4 cup buttermilk

Melt butter in a 10-inch, oven-safe skillet over medium heat. Sprinkle sugar over the butter and, stirring occasionally so the caramel does not stick, cook until golden brown, 3-5 minutes. Add the fruit and stir to glaze the fruit. (The caramel may bind, but it will melt again during baking.) Cook fruit until soft, while stirring, about 10 minutes. Remove from heat. If the fruit seems very juicy, remove up to 1/4 cup of the glaze so that only about 1/4 inch of the caramel juice remains. (The extra can be reserved, refrigerated, for an ice cream topping.) Shake pan or use a spatula to evenly cover the bottom of the pan with fruit. Set aside.

Preheat oven to 350 degrees.

Whisk together first six dry ingredients; set aside. Cream butter and sugar. Beat in vanilla. Add eggs, one at a time, beating well after each addition. On low speed, beat in the buttermilk. (Mixture will look curdled.) Add the dry ingredients in three batches, beating after each addition.

Spread the batter evenly over the cooled fruit in skillet. Bake 35-40 minutes, until the top is a deep brown. (If using gluten-free flour, a tester will come out clean before the cake is fully cooked, so a very brown top will indicate the cake is ready.)

Cool for 10 minutes. Slide a knife around the outside rim of the pan. Invert a plate over the skillet and, using hot pads, firmly hold the plate and skillet together and flip the cake into the plate. Serve warm or at room temperature.

Note: Can also be made with apples or apricots.