01 -
Preheat the oven to 350°F (175°C). Grease a 12-inch springform pan lightly and line the outside with foil to prevent any juice from leaking.
02 -
Soak the apple slices in sugar, cinnamon, and lemon juice. Set aside.
03 -
Stir together all the ingredients for the cake batter. Spread half of the batter in the bottom of the prepared pan.
04 -
Pour the apple mixture and any juice over the batter in the pan. Cover with the remaining cake batter.
05 -
Mix together the ingredients for the streusel topping. Use your hands to form small clumps if desired. If a crumb topping is preferred, omit the butter or oil.
06 -
Sprinkle the streusel topping evenly over the assembled cake. Bake for approximately 75 minutes or until a toothpick inserted into the center comes out clean. Let the cake cool before removing the springform.
07 -
In a small pot, combine butter, brown sugar, and milk. Stir well and bring the mixture to a boil, stirring constantly. Allow it to boil for 2 ½ minutes. Remove from heat, add vanilla, and let cool to room temperature.
08 -
Pour the caramel sauce over the cooled cake. For a thicker sauce, stir in a few tablespoons of powdered sugar. Note that the sauce will remain gooey for about 4 hours but will harden if left overnight.