2Mix all the crust ingredients (graham cracker crumbs, melted butter, granulated sugar and ground cinnamon) in a medium bowl. Set aside about 2 Tbsp (30 mL) for later and press the mixture into a 9-inch deep-dish pie plate in the bottom and up the sides. Bake crust for 10 minutes, it will only brown slightly.
3Combine the vanilla custard filling ingredients (milk, granulated sugar, cornstarch, egg yolks, vanilla extract and salt together) and cook on medium heat, stirring constantly, until it bubbles and thickens to the texture of pudding. Set aside to cool while you make the meringue topping.
4In the bowl of a stand mixer fitted with the beater attachment or in a large bowl using an electric mixer beat the meringue ingredients (egg whites, granulated sugar, cream of tartar) together until it holds stiff and glossy peaks.
5To assemble the pie, pour the filling into the crust and top with a thick layer of the meringue, making little spikes that will brown on top. Sprinkle the reserved crumb over the top and place it into the preheated oven.
6Bake until the meringue browns, around 10 minutes, making sure to watch it carefully.
7Chill in the fridge and eat within a few hours of baking. This pie is best eaten the same day as the meringue will soften and liquify.