Step 1: Prepare the Pie Crust

1. Mix the Dry Ingredients: In a large bowl, whisk together the all-purpose flour, salt, and sugar.
2. Cut in the Butter: Add the cold, cubed butter to the flour mixture. Use a pastry cutter or your fingers to mix until the mixture resembles coarse crumbs. You want to see some small pieces of butter—this is what will make the crust flaky!
3. Add Ice Water: Gradually add the ice water, one tablespoon at a time, mixing until the dough comes together. You might not need all the water, so add it slowly!
4. Chill the Dough: Divide the dough into two discs, wrap them in plastic wrap, and refrigerate for at least 30 minutes. This step is crucial for a flaky crust.

Step 2: Prepare the Apple Filling

1. Slice the Apples: While the dough chills, peel and slice the apples. Aim for uniform slices to ensure even cooking.
2. Mix the Filling: In a large bowl, combine the sliced apples, granulated sugar, cinnamon, nutmeg, lemon juice, and cornstarch. Toss until the apples are well-coated. Set aside to let the flavors meld.

Step 3: Roll Out the Dough

1. Preheat the Oven: Preheat your oven to 350°F (175°C) while you work on the crust.
2. Roll Out the Dough: On a lightly floured surface, roll out one disc of dough to about 1/8 inch thick. Use a round cutter or a glass to cut out circles that will fit your mason jars. You’ll need two circles per jar.

Step 4: Assemble the Pies

1. Fit the Bottom Crust: Place one dough circle into the bottom of each mason jar, gently pressing it down to fit.
2. Fill with Apples: Spoon the apple filling into each jar, filling them about three-quarters full. The apples will cook down, so don’t worry about overfilling!
3. Top with Second Crust: Cut out another dough circle for the top of each pie. You can leave it whole or cut slits for a lattice effect. Press the edges together to seal.
4. Brush with Egg Wash: Brush the top crust with the egg wash for a beautiful golden finish. This is where you can sprinkle a little extra sugar on top for a sweet crunch!

Step 5: Bake the Pies

1. Bake: Place the mason jars on a baking sheet (to catch any overflow) and bake in the preheated oven for 25-30 minutes, or until the crust is golden and the filling is bubbly.
2. Cool: Remove from the oven and let the pies cool for about 10-15 minutes before serving. The jars will be hot, so be careful!

Step 6: Enjoy!

Serve your Mini Mason Jar Apple Pies warm, with a scoop of vanilla ice cream on top or a dollop of whipped cream for an extra treat. They’re not just delicious; they also make for an impressive presentation!