Fat-free Coffee Cake

I got this recipe from Sara's roomate in college because at the time I was trying to lose weight and regulate my eating habits. Fat was the F-word in our family at the time. I was discouraged and had pretty much decided that I was just going to be a really nice fat person but that I was going to eat healthily. It took years but that's what did the trick. I stopped feeling guilty and deprived and weight was not such an issue. Now I eat what I want when I am truly hungry and have become educated in healthy eating.
I was surprised how good this cake tasted despite all the fat-free ingredients.

Sara's roomate's Fat-free Coffee Cake

Mix the following ingredients and put in a 9x13" greased pan.
1/2 cup fat=free dairy sour cream
2 beaten egg whites
1 c. skim milk
3 c. flour
1 1/2 c. sugar
4 tsp. baking powder
1 tsp. salt
Mix the following topping and sprinkle on topof cake batter.
3/4 c. sugar
3 T. flour
3 tsp. cinnamon
3 T chilled butter (Cut into topping mixture.)
Bake 13 min. @ 375 degrees.
10+ min. @ 400 degrees.