In a large mixing bowl, mix all ingredients until the texture is that of a crumble.
Set aside.
Coffee Cake
Pre-heat the oven to 350°F.
In a stand mixer or using a hand mixer, cream the soft butter, white sugar, sour cream, vanilla, and eggs.
Add the baking soda and baking powder.
Slowly add the flour. Be careful not to overmix the ingredients.
Once all of the ingredients are mixed well, pour the batter into a greased tube or bundt pan in alternating layers with the crumble – start with the cake batter, then add crumble, and repeat three times. Top with the remaining crumble.
Bake for 1 hour or until a knife inserted into the cake comes out clean.