The smell of this delicious cinnamon coffee cake wafting through the house while baking is absolutely irresistible! Served warm out of the oven it's heavenly.
Preheat oven to 325 degrees. Grease a 9 x 9 inch pan with butter.
Sift together flour, baking soda, baking powder and salt; set aside.
In a large mixing bowl, beat butter and sugar together until creamy.
Add the eggs, sour cream, and vanilla to the butter/sugar and mix well.
Slowly add the flour mixture while beating at low speed until fully incorporated.
Combine the topping ingredients.
Put half the batter in the greased 9 x 9 pan (it will be very thick.) Sprinkle with half the topping. Layer the remaining batter on top and cover with the other half of the topping.
Bake for 35-40 minutes at 325 degrees or until toothpick inserted in center comes out clean.
Notes
When adding the second layer of batter, because it is so thick it is best to use a tablespoon to dollop it evenly over the top, then very gently spread it with a flat spatula or the back of a spoon to cover the center cinnamon layer so as not to mix the cinnamon topping into the batter.Cake is finished when a wooden toothpick inserted in the center comes out clean.Wrap tightly to store for up to two days or freeze for up to two months.