Preheat oven to 350 degrees F. Prepare a 9 x 13in baking pan or dish by lightly greasing with vegetable oil or butter.

Separate 1 cup cake mix from the other ingredients.

Combine the rest of the cake mix with an egg and melted butter, mixing until well blended and no longer lumpy.

Spread the mix in the bottom of the baking dish.

In another bowl, mix together pumpkin, milk, the remaining 3 eggs, and spices. Mix until combined and pour this mixture over the layer already in the baking dish.

Use a food processor or pastry cutter to combine chilled butter and sugar with the 1 cup of cake mix that was set aside earlier. Process or cut together until the mixture resembles pea-sized crumbles. Mix in walnuts by hand.

Spread crumble mixture over the top layer in the baking dish.

Bake 45 – 50 minutes until golden brown.