In a bowl, mix the ingredients for the crumb toppings. Set aside.
In a second larger bowl, mix the butter and sugar together.
Add the eggs in one at a time, mixing after each egg is added.
Mix in the vanilla and sour cream.
Add in the remaining ingredients.
Cut a sheet of parchment paper long enough to cover the bottom of the crock-pot (need 4 qt or larger) and the sides. Fit the parchment paper in the bottom of the crock-pot.
Pour the cake mix in the crock-pot.
Sprinkle the crumb topping on top of the batter.
Cover and Cook on HIGH for 2 hours or or until a toothpick inserted in the middle of the cake comes out clean.
Remove the parchment paper and the crumb cake from the crock-pot. Slice and serve with coffee.