Favorite Coffee Cake

Back in the mid-70's, I found this recipe in a Family Circle magazine (I think!)

CAKE:
1 and 1/2 cups all-purpose flour
1/2 cup granulated white sugar
1/4 cup brown sugar, packed
2 and 1/2 teaspoons baking powder
1/4 teaspoon salt
3/4 cup of milk*
1/4 cup butter, softened
1 large egg, slightly beaten

Beat everything together and pour into a greased 9-inch round layer cake pan.  Set aside while you prepare the topping (recipe below).

*  I've never tried the following variation, but, ...IF you use buttermilk in place of regular milk, read this first and proceed accordingly:

"If you want to substitute 1 cup of buttermilk for the sweet milk, blend 1/2 teaspoon of BAKING SODA into the flour and use only 1/2 teaspoons of  BAKING  POWDER. 


In other words, 1/2 teaspoon of baking soda plus 1 cup of buttermilk (or an equivalent) can replace about 2 teaspoons of the baking powder."

TOPPING:
1/3 cup brown sugar, packed
1/4 cup all-purpose flour
1/2 teaspoon cinnamon
3 tablespoons firm butter

Mix/cut all topping ingredients together until crumbly and then evenly sprinkle this topping onto batter and bake in oven at 350-degrees for about 25-30 minutes.