Grease and flour a 8x8 pan or round pan
Cream together 1/2 cup butter, eggs, and sugar until fluffy use ele. mixer and large bowl.
add sour cream, vanilla,flour, baking powder, baking soda, salt. Mix until smooth.
in small bowl, mix together br. sugar, 2 tbsp. butter
cinn. and 2 tbsp. flour with a blending fork.
Spoon 1/2 of batter in the pan
sprinkle 1/2 of crumb topping over batter
rest of batter and sprinkle rest of topping over batter.
Bake 350 for 50-60 minutes or ti;; toothpick comes out clean.