Preheat oven to 350ºF.
Add the graham crackers and cinnamon to a food processor and process until fine. Add the melted butter to the bowl and pulse the machine until it's fully incorporated into the crumbs and the graham crackers look like wet sand. Line a 9-inch pie plate with the crumb mixture and press the crust down into the bottom and up the sides so that it's evenly dispersed. Bake until the crust has set and feels slightly crisp, 10-12 minutes. Remove from the oven and cool completely.