Preheat oven to 400°F (200°C). Take store-bought pie crust out of the refrigerator and let it sit on the counter for 15 minutes.

Peel, core, and slice 4 apples into 0.25 inch slices. Place the apples into a large bowl.

Toss apples with lemon juice.

Mix cinnamon, 0.25 cup granulated sugar, and 0.25 cup all-purpose flour in with the apples, so that all the apples are coated evenly.

Transfer apple mixture to a medium-sized pan, add butter on top, and cover with a lid. Over medium heat, bring the apples up to a simmer and stew them until they are soft.

Take 2 discs of store-bought pie crust and carefully unroll them. They should be easy to roll out without breaking the dough.

Using a large, 3.25-3.5 inch biscuit cutter, cut 12 circles out of the dough.

Carefully press a dough circle into the bottom and sides of a muffin tin. Do this to line all 12 muffin tin cups.

Fill each muffin tin with 2 tablespoons of the prepared apple pie filling.

Cut 0.25 inch strips from the remaining dough for the lattice top. Remove every other strip and weave them cross-wise with the other strips.

Using a 2.5 inch biscuit cutter, cut 12 lattice top circles and place each on top of a mini pie in the muffin tin.

Whisk together 1 egg and 1 tablespoon water to make an egg wash. Use a pastry brush to dab a little on the top of each mini pie.

Sprinkle the top of each mini pie with a little turbinado sugar for that finishing touch.

Place the muffin tin pan on a baking sheet lined with parchment paper to catch any baking spills. Bake for 15 minutes at 400°F (200°C).