Preheat the oven to 375°F. Lightly grease the inside of a 9-inch springform pan. Optional: I also like to place parchment paper on the bottom and the sides for added ease in removing the pie from the pan and keeping the crust intact. Set the pan aside.
In a large food processor, process the graham cracker sheets until they turn into fine crumbles.
Add the melted butter, brown sugar, cinnamon, and salt, and process until well combined.
Press the graham cracker mixture into the prepared springform pan so that the bottom layer is even. You can press some of the mixture to go slightly up the sides around the edge if you like.
Bake at 375°F for 7-10 minutes, until the crust is golden brown. While the crust is baking, make the sweet potato pie filling.
Make the sweet potato pie filling
In a large bowl whisk together the sweet potato pie mix from two cans, the evaporated milk, eggs, vanilla, and cinnamon.
Pour the filling into the pre-baked graham cracker crust.
Bake at 400°F for 15 minutes. Then lower the heat to 375°F and continue baking for 35 to 45 minutes. The middle might have a slight jiggle but it should not be too jiggly.
Cool completely, then refrigerate for at least 30 minutes before serving.
Notes
Makes 8-10 servings. Storage: store in an airtight container in the refrigerator for up to 5 days. Freeze: wrap in plastic wrap, then store in a freezer bag or freezer safe container for up to two months.