Prepare the Apple Filling:

• In a medium saucepan, combine diced apples, sugar, cinnamon, nutmeg, lemon juice, and cornstarch.
• Cook over medium heat, stirring occasionally, until the apples soften and the mixture thickens (about 5-7 minutes).
• Remove from heat and set aside to cool.

Make the Cookie Dough:

• Preheat the oven to 350°F (175°C) and line a baking sheet with parchment paper.
• In a large bowl, whisk together flour, baking powder, salt, and cinnamon.
• In a separate bowl, cream together butter and sugar until light and fluffy.
• Beat in the egg and vanilla extract, then gradually add the dry ingredients, mixing until a dough forms. Add milk to bring the dough together if needed.

Assemble the Cookies:

• Roll the dough into tablespoon-sized balls and flatten them slightly on the prepared baking sheet.
• Place a teaspoon of the apple filling in the center of each cookie.
• Fold the edges of the dough over the filling to form a pocket and pinch the edges to seal.
• Repeat with the remaining dough and apple filling.

Make the Streusel Topping:

• In a small bowl, combine flour, oats, butter, brown sugar, and cinnamon.
• Use a fork or pastry cutter to mix until the mixture forms crumbs.
• Sprinkle the streusel topping evenly over each cookie.

Bake the Cookies:

• Bake for 12-15 minutes, or until the cookies are golden brown and the apple filling is bubbly.
• Let the cookies cool on the baking sheet for a few minutes before transferring to a wire rack to cool completely.

Serve & Enjoy!

• Serve warm or at room temperature. You can also drizzle with a little caramel sauce for extra sweetness!