01 -
Preheat your oven to 350°F (175°C). Grease a 9-inch pie dish.
02 -
In a medium bowl, combine graham cracker crumbs, sugar, and cinnamon (if using). Stir in melted butter until the mixture resembles wet sand. Press the mixture firmly into the bottom and sides of the pie dish to form the crust.
03 -
Bake the crust in the preheated oven for about 8-10 minutes, or until lightly golden. Remove from oven and set aside to cool.
04 -
In a saucepan over medium heat, whisk together brown sugar, flour, and salt. Slowly add milk, whisking constantly to avoid lumps. Cook, stirring occasionally, until the mixture thickens and begins to boil.
05 -
Gradually pour a small amount of the hot mixture into the beaten egg yolks to temper them. Stir well, then slowly whisk the egg mixture back into the saucepan.
06 -
Cook for an additional 2-3 minutes, stirring constantly, until the filling is smooth and thick.
07 -
Remove saucepan from heat and stir in butter and vanilla extract until fully incorporated and smooth.
08 -
Pour the butterscotch filling into the cooled graham cracker crust. Smooth the top with a spatula.
09 -
Allow the pie to cool at room temperature for about 30 minutes, then refrigerate for at least 3 hours, or until fully set.
10 -
Before serving, top the pie with whipped cream if desired. Slice and enjoy!