My husband's favorite cake always sinks in the middle. It thoroughly frustrates me. It's a loaf cake with 1/2 buttermilk, 1& 1/2 cups flour, and 1/2 tsp. baking soda. Can I change the the baking soda amount to 1/8 tsp and add 1 1/2 tsp. baking powder? Will this prevent the cake from sinking? Or totally mess up the recipe?