Cream together the butter , sugars, eggs and vanilla. Add the dry ingredients and combine.
Add sour cream and egg nog to mixture and mix until you have a nice cake batter.
Pour the cake batter into a prepared 9x9 baking dish and spread into an even layer.
Combine the crumb mixture ingredients and sprinkle liberally over the top of the cake.
Bake in a 350 degree oven for 40-45 minutes or until a toothpick comes out with only a few crumbs. T