For the Batter
2 tablespoons unsalted butter
3 large Granny Smith apples (cored, peeled, and sliced)
Streusel Topping (recipe follows)
Caramel Sauce (recipe follows)
1/2 cup unsalted butter, softened
1 cup sugar
2 large eggs, at room temperature
2 cups all-purpose
2 teaspoons baking powder
1/2 teaspoon salt
2/3 cup milk
2 teaspoons pure vanilla extract
Preheat oven to 350° F (About 180° C). Grease and flour a 9-in (22.5 cm) springform pan. Reserve.
Melt 2 Tbsp. butter in a large skillet over medium-high heat; add the apples; sauté for 5 minutes or until softened.
Remove from heat; cool completely (about 30 minutes). Meanwhile, prepare the Streusel Topping and Caramel Sauce. Reserve 1/2
cup Caramel Sauce to drizzle the cake with just before serving. At medium speed, beat the butter with an electric mixer until creamy;
gradually add sugar, beating well. Add eggs, one at a time, beating
after each addition until well blended. In a separate bowl, combine
flour, baking powder, and salt. Beginning and ending with this flour
mixture, add to the butter mixture alternately with the milk, beating at
low speed until well blended after each addition. Stir in the vanilla. Pour batter into the prepared pan, top with apples, drizzle with 1/2 cup Caramel Sauce; then, sprinkle with Streusel Topping. If using a dark, coated springform pan, bake at 325° for 45 minutes (if
using a noncoated shiny springform pan, bake at 350° for 45 minutes).
After these 45 minutes, cover loosely with aluminum foil in order to
prevent excessive browning; bake for additional 25 to 30 minutes or
until center is set (note: wooden toothpick will not come out clean due
to the caramel).