GINGERBREAD COFFEE CAKE

1 box light brown sugar
1 1/2 sticks butter
2 c. flour
2 eggs
1 c. buttermilk
1 tsp. nutmeg
1 tsp. ginger
2 tsp. cinnamon
1 tsp. soda

Mix first 3 ingredients well. Reserve 1 cup. Add remaining ingredients and mix well with mixer. Pour into greased, floured 9x13 inch pan. Top with reserved cup of mix. Bake at 350 degrees for 40 minutes.