Preheat oven to 350 F.

In large bowl, cream butter. Gradually add sugar, beating until light and fluffy.

Add vanilla and eggs, beat.

Sift together dry ingredients.

Gently stir in half the dry ingredients and half the sour cream. Repeat.

Grease selected cake pans – two 8-inch round OR two 8-inch square OR one 9x13-inch pan.

To make topping, in medium bowl, mix topping ingredients with a fork until crumbly.

Spread half of batter in pan and sprinkle with half of topping. Carefully add rest of batter and remaining topping. Sprinkle with cinnamon if desired.

Depending on pan(s) used, bake 30 minutes for 8-inch rounds, 35 minutes for 8-inch squares or 45 minutes for 9x13-inch pan. When coffee cake is done, center should spring back to a light finger touch.