overnight coffee cake

Overnight coffee cake
1/3 cup butter, softened
1/2 cup white sugar
1/4 cup brown sugar
1 egg
1 cup flour
1/2 t baking powder
1/4 t baking soda
1/2 t ground cinnamon
1/2 cup buttermilk
1/4 cup brown sugar
1/4 cup finely chopped walnuts or pecans
1/4 t cinnamon
Grease an 8 inch square baking pan. In a large bowl, cream the butter and the sugars. Add the egg, mix until well combined. In a separate bowl, combine all of your dry ingredients. Stir the flour mixture into the creamed mixture alternately with the buttermilk. Spread evenly into baking dish.
In small bowl mix the topping ingredients and sprinkle over the batter. Cover and refrigerate overnight. Bake the cake for 45 minutes at 350 or until a toothpick inserted in the center comes out clean. Serve this with a mug of hot cocoa.