Prep: Preheat oven to 350° F. Spray a 9x13 inch pan with nonstick spray and line with parchment paper so you can lift the bars out for serving later.
Make the Crust: Pulse the biscoff cookies in a food processor until you have fine crumbs. In a medium bowl, melt the butter and stir in cookie crumbs. Press crust mixture into prepared pan. Bake this for 10 minutes. Set aside. Keep the oven at 350℉.
46 whole biscoff cookies, 1/2 cup salted butter, melted
Make the Pumpkin Pie Filling: In a large bowl, whisk together the pumpkin, evaporated milk, heavy cream, eggs, vanilla, maple syrup, and brown sugar. Then, whisk in the spices and corn starch.
2 and 2/3 cups pumpkin puree, 1 can evaporated milk, 1/2 cup heavy cream, 2 large eggs, at room temperature , 1 tsp vanilla extract , 1/4 cup maple syrup, 1 cup + 2 tbsp dark brown sugar, packed, 1/2 tsp salt, 4 tsp cinnamon, 2 tsp ground ginger, 1 tsp nutmeg, 1/2 tsp ground cloves, 1/2 tsp allspice, pinch of black pepper, 5 tsp corn starch
Bake: Pour filling over the pre-baked crust. Bake at 350℉ for 50 to 56 minutes. When the bars are done, the edges will appear set and the center will have a slight wobble. A toothpick inserted into the center should leave a defined hole - if the filling is too runny, that hole won't look defined (see photo above). The internal temp of the center of the bars should be about 190℉ to 198℉.
Cool the Bars: Let bars cool on a wire rack on the counter for an hour or so, then transfer to the fridge to cool for another hour (or until chilled), before slicing and serving.
Make Whipped Cream: Make this only when you are ready to serve the bars. Visit my recipe on How to Make Homemade Whipped Cream for directions on how to make the whipped cream, and how to stabilize it if you plan on piping it like I did. 3 tbsp powdered sugar , 1 tbsp vanilla extract, pinch of nutmeg, to taste, 3/4 cup cold heavy cream
Serve & Store: Slice the bars into 12 squares or up to 24 squares (or however many you need!), then pipe on whipped cream, or let guests dollop it on themselves. Store leftover bars and whipped cream in an airtight container in the fridge for 3-4 days.