Preheat oven to 350 degrees. Spray a 9-inch cast iron skillet with cooking spray and set aside.
Toss the apples and pecans with the bourbon and set aside.
In the bowl of a stand mixer, whip together the butter and 1 cup of the sugar until pale and fluffy, 3 - 4 minutes.
Add the eggs and vanilla and beat until smooth.
In a medium bowl, whisk together the flour, baking powder and salt.
Add the flour mixture and sour cream to the batter and beat on low until a smooth batter forms.
Fold in bourbon soaked apples and pecans. Spread the batter in the prepared skillet.
Sprinkle the remaining 1/4 cup of sugar evenly over the top of the cake batter.
Bake until a wooden pick inserted in the center comes out clean, 35-40 minutes. Let the cake cool in the skillet.
Serve cake slices topped with scoops of butter pecan ice cream.