Make the cinnamon crunch: Preheat the oven to 350 degrees F. Combine the flour, oats, light muscovado sugar and cinnamon in a food processor and process a few times to combine. Add the butter and pulse until combined. Pat the mixture evenly into a 4-inch square on a parchment-lined baking sheet. Bake until golden brown and crisp, 20 to 25 minutes. Let cool. Transfer to a cutting board and chop into small pieces. Keep the oven on.
Make the crust: Combine the graham cracker crumbs, melted butter and cinnamon in a bowl and mix until combined. Press evenly into the bottom and up the sides of a 10-inch pie plate. Brush with the beaten egg. Bake until golden brown and firm, about 12 minutes. Let cool on a rack.
Reduce the oven temperature to 300 degrees F. Make the filling: Whisk the eggs, egg yolks, dark muscovado sugar, granulated sugar and molasses in a medium bowl. Whisk in the pumpkin puree, cinnamon, ginger, nutmeg, cloves and salt. Whisk in the heavy cream, milk and vanilla seeds or extract. Strain the mixture through a coarse strainer into a bowl. Whisk in the melted butter.
Place the pie plate on a baking sheet, pour the pumpkin filling into the crust and sprinkle additional cinnamon over the top. Bake until the filling is set around the edges but the center still jiggles slightly when shaken, about 1 hour 15 minutes. Transfer to a rack and let cool to room temperature, about 2 hours.
Make the whipped cream: Combine the heavy cream, vanilla seeds, maple syrup and bourbon, to taste, in a large chilled bowl and whip until soft peaks form. Top the pie with the whipped cream and cinnamon crunch.
Top off your feast with one (or more!) of these tasty pies.