In a bowl, combine the flour, almond flour, and salt.
In another bowl, add the powdered sugar, butter, and vanilla. Beat with a hand mixer just until well combined and creamy. Do not beat until fluffy.
Add half of an egg and beat until fully incorporated.
Add the dry ingredients and beat until just combined. Wrap the dough in plastic wrap and freeze for 10 minutes, or until it is well chilled but still pliable.
Preheat the oven to 350F (180C). Prepare a 12-cup muffin pan. I like to line each cup with a strip of parchment paper so it's easier to remove the cookies after baking. If you have only a 6-cup muffin pan, bake the cookies in two batches.
Roll out the dough on a floured surface or between two sheets of parchment paper until it is ⅙ inch (4mm) thick. Cut out 12 rounds using a 3-inch (7cm) round cookie cutter. Collect the dough scraps and reroll as needed, adding flour as needed.
Line each muffin cup with a dough round. Press gently so the dough takes the shape of a bowl. Add the apple filling, approximately 2-3 teaspoon per cookie, and spread it evenly.
Bake for about 14 minutes, or until the edges start to turn golden.
Allow the cookies to rest in the muffin pan for 5 minutes. Then remove onto a cooling rack to cool completely before serving.