Grab a cup of coffee and a slice of this cake. It is better than Calgon.
1-1/2 stick butter, softened.
2 cups sugar
3 cups sifted flour
4 teaspoons baking powder
1 teaspoon salt
1-1/4 cup buttermilk
3 whole egg whites, beaten until stiff
FOR THE TOPPING:
1-1/2 stick butter, softened
3/4 cups flour
1-1/2 cup brown sugar
2 Tablespoons cinnamon
Preheat oven to 350 degrees. Sift together flour, baking powder, and salt. Beat egg whites and set aside.
Cream butter and sugar. Add flour mixture and milk alternately until combined. Don’t overbeat. Fold in beaten egg whites with a rubber spatula. Spread in a well-greased 9 x 13 baking pan.
In a separate bowl, combine topping ingredients with a pastry cutter until crumbly. Sprinkle all over the top.
Bake for 40 to 45 minutes until toothpick comes out dry in cake part. Cinnamon/sugar/butter mixture part will still be sticky.
I got the recipe here.