Freeze the butter for 15 to 30 minutes.

Add the flour and salt to a large bowl. Remove the butter from the freezer and grate it into the flour mixture using the large side of a box grater. Gently massage the butter into the flour with your fingers until it's crumbly but still clumpy. Add half of cold water and gently bring the mixture together. Add the rest of the water and bring it together into a rough dough. Do not overmix, the dough does not need to be smooth and perfect, just mixed enough to hold together. Shape the dough into a rough disc, wrap it in plastic wrap and leave in the fridge for 1 hour.

Chop up the apples whatever way you prefer, but keep in mind that they need to be small enough to fit easily into your muffin tins so I cube the apples. Cut them in half and remove the core and stem. Then slice each half into 6 to 8 pieces lengthwise and then into 4 to 6 pieces widthwise.

Scoop the apple pieces into a bowl and add the brown sugar, cinnamon, corn starch, lemon juice and zest. Mix them up and set aside.

When you are ready to start assembling the pies, turn the oven to 400 F. Butter or oil 6 muffin cups.

Remove the dough for the crust from the fridge. Divide the dough into 6 pieces and roll each piece into a small ball.

Sprinkle the counter with flour and one at a time, roll out each piece of dough into circles approximately 5 to 6 inches across. Be sure to sprinkle more flour between each roll out to make sure the dough doesn't stick to the counter. The circles should not be perfect, just basically round with jagged edges. Rustic is the look here so don't worry about perfection.

Carefully the place the circles of dough into each muffin tin, gently pressing them down into the corners. Be sure to leave the crust edges hanging over the top edges of the tin. These will be the pie crusts.

Fill each pie dough lined tin with apple mixture and fold the edges of the dough over the top. You should still have some apple mixture poking out the top.

Whisk the egg in a small bowl and use a pastry brush to brush egg over the top of each mini pie. (This step is optional. It just makes the tops more golden and pretty)

Bake for 30 minutes or until the tops are golden brown and the apples are gooey and bubbling.

Once they are cool enough to touch use a butter knife to gently unstick the edges of the pie from the tin and remove onto a plate for serving.

Dust them with a little powdered sugar for extra presentation points and serve!