Mix these with a pastry blender til crumbly.
Reserve 2/3 C of mixture to topping.
To the above mix add:
1 cup sour cream
1/2 tsp baking soda
1 tsp baking powder
Beat thoroughly, pour into well buttered 8 x 8 pan.
ADD: 2 finely chopped nuts to crumb mixture, sprinkle over to of streusel.
Bake at 375 degrees or until prettily browned.