- 1 cup unsalted butter
- 1 cup water
- 2 cups + 2 tablespoons all-purpose flour
- 2 cups granulated sugar
- 1/2 teaspoon salt
- 1 teaspoon baking soda
- 1 teaspoon cinnamon
- 1/2 cup sour cream
- 2 eggs
- 1 medium apple , diced small (about 1 1/4 cups)
For The Icing
- 3 tablespoons milk
- 1/4 cup unsalted butter
- 2 cups powdered sugar
- 1/2 teaspoon vanilla extract
- 2 tablespoons caramel topping
- Preheat oven to 350 degrees F. Lightly coat a 10x15 inch jelly roll pan with nonstick cooking spray.
- In a medium saucepan, bring butter and water to a boil, stirring frequently to prevent burning. Remove from heat and allow to cool.
- In the meantime, in a large bowl, whisk together the flour, sugar, salt, baking soda, and cinnamon. In a separate bowl, whisk together the sour cream and eggs. Combine the wet ingredients with the dry. Fold in the diced apples. Gradually stir in the warm melted butter and mix well.
- Pour batter evenly into the prepared pan (batter will be loose.) Carefully transfer to the oven and bake for 25-27 minutes, until the center of the cake springs back when touched. Let cool for 20 minutes.
- Make the icing by combining the butter and milk in a medium microwave safe bowl; microwave for 45 seconds, and then in 15 second intervals until butter is melted. Whisk to combine. Add in the powdered sugar, vanilla, and caramel topping; whisk to combine (add more powdered sugar or milk to get the right consistency - you want the icing to pour, but thick enough that it doesn't pool over the sides of the pan.)
- Pour icing over the cake while it’s cooled, but still slightly warm. Allow to set for about 15-20 minutes.
- Slice into squares and enjoy!