New Jersey Crumb Cake

This brings back so many memories of growing up on Sunday mornings and after church make a run to a local NJ deli that had donuts on Sundays.  Except this is even better cause you are making it fresh!  Really easy to make.  To make this you will need:
Topping
1/2 cup butter softened
1 cup sugar
1 package Jiffy Buttermilk biscuit mix
2 teaspoons cinnamon
Cake
1/2 cup butter softened
1 cup sugar
2 large eggs
3/4 cup milk
1 teaspoon vanilla
2 tablespoons sour cream
2 cups flour
2 teaspoons baking powder
1/2 cup cinnamon chips (optional)
1/4 - 1/2 cup confectionery sugar.
1.)  In a small bowl, combine all the ingredients for the topping.  Put in the refrigerator for at least one hour.  This makes it easier to crumb over the cake.
2.)  Preheat the oven to 350 degrees.  Spray a 9 x 13 pan with Pam.
3.)  In a medium bowl, cream the butter and the sugar with an electric mixer.  Add in the eggs, milk, vanilla and sour cream.  Cream this in.  Add in the flour a cup at a time.  Add in the baking powder.  If you are adding cinnamon chips, stir them in now.
4.)  Pour the batter into the prepared pan.  Bake for 15 minutes.  Bring the pan out of the oven.  Crumb the topping over the top of  the cake.  Return the cake to the oven and continue baking for another 30 - 40 minutes, or until a toothpick inserted in the cake comes out clean.
5.)  Once the cake is cool, sift with confectionery sugar and enjoy!