Preheat oven to 375F and line an 8x8 baking pan with parchment paper.

Blend graham crackers into crumbs in a food processor. Mix crumbs with the melted butter until evenly combined.

Press breadcrumb butter mixture into an even layer in the bottom of the pan. I use the bottom of a measuring cup to make sure its flat.

In a large mixing bowl whisk pumpkin puree, heavy cream, eggs, and brown sugar together until smooth. Then, whisk in cornstarch and pumpkin pie spice.

Pour pumpkin mixture into the baking pan over the crust and carefully place in the oven. Bake at 375F for 45 minutes. The center should jiggle a little while hot, but will set fully as it cools. Allow to cool completely before cutting into squares and serving with whipped cream or ice cream! Store leftovers in an airtight container in the refrigerator.