Reserve one cup of the cake mix in a small bowl. Mix together remaining cake mix, melted butter, and 1 egg. Press into the bottom of a 9x13 pan that has been sprayed with cooking spray.

Mix together pumpkin butter, milk, and 2 eggs. Pour over the crust.

Add the flour, sugar, and butter to the reserved cake mix. Use a fork or pastry cutter to cut the butter until it resembles small peas. Sprinkle over the pumpkin butter layer.

Bake in a preheated 350 degree oven for 35 to 40 minutes. Cool completely and cut into squares. Sprinkle with powdered sugar.