Combine graham cracker crumbs and 1 1/2 bananas in a food processor until combined. (If you don’t have a food processor, mash your bananas in a large bowl until smooth, then stir in the graham cracker crumbs.) Put the crust into a 9-inch pie plate. My favorite part of a pie is the crust so I made this one pretty thick. If you don’t like your crust as thick, use less of the mixture. Press firmly in the bottom and up the sides to make sure that the crust is in tact and won’t break when you cut into it. I like to use the bottom of a glass to get the crust really firm in the bottom of the pan. Put the crust in the fridge while you work on the filling.