Preheat the oven to 350 degrees Fahrenheit.
Melt the stick of butter, for the topping.
In a medium bowl, combine the ingredients, except butter, for the topping. Once the butter has melted, add it and continue mixing. It should have a sand-like consistency.
In a large bowl, beat the sugar and butter for the cake batter together until creamy. Beat in the eggs and vanilla.
In a medium bowl, combine the flour, baking soda, salt and spices for the cake batter.
Add 1/4 of the sour cream and the previously mixed flour and spice mixture into the cake batter. Continue adding and mixing until all is combined. If using brandy, rum, or both, add them in and mix until combined.
Cut two apples into very thin slices.
Line a 9”x13” pan with parchment paper. Pour half the cake batter into the parchment paper-lined pan.
Set the apple slices uniformly on the batter, until they are all used up.
Optional: Cover the apples in a light layer of the streusel topping.
Cover the apples with the rest of the batter.
Cover the remaining batter with the streusel topping.
Bake for 45-55 minutes, until a pick placed into the middle of the cake comes out clean.