Pumpkin Pie Cake

2 cans pumpkin ( 16 oz. cans.)
1 --12 oz. can evaporated milk
2 large eggs
2 egg whites
1 cup sugar
2 tsp. cinnamon
1 tsp. nutmeg
1/2 tsp. ginger
1/2 tsp. cloves
1--18.5 oz. yellow cake mix
1 cup chopped black walnuts
5 Tbsp. butter--melted
1/3 cup sour cream--room temperature
1/3 cup orange juice--room temperature
Cool Whip

Heat oven to 350 degrees. Line a 9 x 13 baking pan with parchment paper.
Combine pumpkin, evaporated milk, eggs, egg whites, sugar and spices. Mix with mixer until blended. Spread pumpkin mix over parchment paper and level our with spatula.
Sprinkle the cake mix over the pumpkin mixture, then sprinkle the walnuts over the cake mix. Gently pat down. Blend melted butter with sour cream and orange juice. If the juice and sour cream are cold the butter will harden. All need to be room temperature. Drizzle over the nuts and cake mix. Bake for about 60- 65 minutes-- test the pumpkin layer as you would a pumpkin pie. Knife needs to come out relatively clean. Let the cake cool--- then invert on a larger pan or dish, pull off the parchment paper and cut in squares. If desired cover with cool whip on top.