Preheat your oven to 350°F (175°C).

In a mixing bowl, combine crushed Ritz crackers and melted butter.

Press the cracker mixture into the bottom and up the sides of a 9-inch pie pan.

In another bowl, mix the sliced apples, sugar, cinnamon, lemon juice, cornstarch, and vanilla extract.

Pour the apple mixture into the prepared crust.

Optionally, sprinkle some extra crushed Ritz crackers on top.

Brush the edges of the crust with the beaten egg.

Bake in the preheated oven for about 45 minutes until the apples are tender and the crust is golden.

Let the pie cool slightly before slicing.