First, make the Streusel: combine the flour powdered sugar and cinnamon in a bowl, and stir well to blend. Add the melted butter, and mix to coat all the flour mixture in the butter, until it forms small pea size particles. Place the mixture on a Parchment paper lined cookie sheet, and place in the oven at 400 degrees for about 20 minutes, or until the topping is golden brown. Turn the topping/Streusel mixture half way through baking with a spatula, to make sure it bakes evenly. When the streusel is golden brown, remove the cookie sheet to a wire rack to cool.

Make the crust: Combine the flour and powdered sugar until mixed. Add the melted butter, and coat the flour in the butter until it forms a thick ball. Press the mixture into a 9 X 9 baking dish, and place in the oven at 400 for 20 minutes. Remove and set aside. In the mixing bowl of a stand mixer, place the pumpkin, eggs, milk, and vanilla, and mix until well blended. Add the cinnamon and allspice, and mix on medium speed for about 1 minute until completely combined. Pour the pumpkin filling on top the crust in the 9 X 9 pan, and place it back in the oven and bake at 350 for 45 minutes or until a toothpick in the center comes out clean. When the pumpkin is done, remove it to a wire rack to cool, and spread the streusel topping evenly over the pumpkin. Let cool for at least 2 hours, and when ready to serve, cut into 2 X 3 inch squares, top with whipped cream and a sprinkle of cinnamon. Enjoy!