Follow these easy steps to create your Apple Pie Cookies:

1. Preheat Oven: Preheat your oven to 375°F (190°C). Line a baking sheet with parchment paper.
2. Prepare Dough: In a large bowl, whisk together flour, granulated sugar, baking powder, baking soda, and salt. Add the softened butter and mix until crumbly.
3. Add Wet Ingredients: Incorporate the egg, milk, and vanilla extract into the flour mixture. Stir until the dough comes together.
4. Chill the Dough: Wrap the dough in plastic wrap and refrigerate for at least 30 minutes to firm up.
5. Prepare Filling: In a bowl, combine the diced apples with lemon juice, cinnamon, nutmeg, brown sugar, and cornstarch. Mix until evenly coated.
6. Roll Out Dough: On a floured surface, roll out the chilled dough to about 1/8 inch thick. Use a round cookie cutter or glass to cut out circles.
7. Fill Cookies: Place a tablespoon of the apple filling in the center of half of the dough circles. Leave a bit of space around the edges.
8. Seal the Cookies: Top with the remaining dough circles and press the edges to seal. Optionally, you can crimp the edges with a fork for a decorative touch.
9. Brush with Egg Wash: If desired, brush the tops of the cookies with the egg wash to give them a golden finish.
10. Bake: Bake in the preheated oven for 20-25 minutes, or until the cookies are lightly golden brown.
11. Cool on Wire Rack: Remove from the oven and let cool on a wire rack for about 10 minutes. Dust with powdered sugar if desired.

These simple steps will guide you toward baking irresistibly delicious Apple Pie Cookies that everyone will love!