Gather all the ingredients and prepare your workspace so everything is within reach.
In a mixing bowl, combine the graham cracker crumbs, sugar, melted butter, and cinnamon if using, and mix until the texture resembles damp sand and everything is evenly coated.
Transfer the mixture into a 9-inch pie plate and press it firmly into the bottom and up the sides, making sure the layer is even and compact.
For a no-bake crust, chill the prepared crust in the refrigerator until firm before adding your filling.
For a baked crust, place it in a preheated oven at 350°F (175°C) and bake until lightly golden and set, then allow it to cool completely before using.