Pumpkin Cake

29 oz. pumpkin puree
3 well beaten eggs
1 cup milk
1/2 cup sugar
1/2 cup brown sugar
1/2 tsp. salt
1 3/4 tsp. pumpkin pie spice
1 packaged cake mix- white or yellow
1 cube melted butter

Mix all ingredients together except for cake mix and butter.  Pour into 9 x 13 pan.  Sprinkle cake mix over top of pumpkin mix.  Drizzle melted butter on top of cake mix. 

Bake 1 hour at 325 degrees.  You may serve with cool whip or ice cream.