For the Crust: Heat the butter in a small sauce pan over medium low heat. Once melted, remove from heat and whisk in the brown sugar, maple syrup, salt and cinnamon. Set aside to cool.
Crush the corn flakes in a ziplock bag in a food processor until you have a mixture of coarse crumbs and small flakes. Don’t turn them completely into powder.
In a large mixing bowl, combine the crushed cornflakes and the butter mixture and toss until evenly coated. The mixture should clump when squeezed. Transfer into a greased 9-inch deep-dish pie plate. Use a flat-bottomed measuring cup to firmly press into the bottom and sides of the pan.
Bake at 350°F for 10-12 minutes, until golden and fragrant. Remove from the oven and while the crust is still hot, carefully re-press with the flat bottom measuring cup until compacted. Let cool completely so the sugar-butter mixture firms up.
For the filling: Combine all ingredients in a large mixing bowl and whisk until homogenous. For ease, you can blend the mixture using a stand mixer, hand mixer, immersion blender, or standard blender. Be sure to blend just until combined.
Pour into par baked crust and transfer to a 325 degree oven, along with a water bath if using (below) until the edges are set and the center 3 inches is still slightly wobbly, about 50-60 minutes.
Water Bath (optional but encouraged): place ice cubes on a baking sheet or an oven safe pan of any size and position on the lower rack of the oven while the pie bakes. Refill with additional ice (or water) until the pie has finished baking.