01 - Preheat oven to 325°F. Line two baking sheets with parchment paper.
02 - Whisk together the all-purpose flour, almond flour, baking powder, and salt in a medium bowl.
03 - Beat the softened butter and sugar in a large bowl until light and fluffy, about 2-3 minutes.
04 - Add the egg, almond extract, and vanilla extract to the butter mixture. Beat until well combined. Reserve half the egg yolk for later.
05 - Gradually add the dry ingredients to the wet mixture, mixing just until a soft dough forms.
06 - Scoop tablespoon-sized portions of dough and roll into balls. Place them 2 inches apart on the prepared baking sheets.
07 - Flatten each dough ball slightly and press a whole almond into the center of each cookie.
08 - Mix the reserved egg yolk with 1 tablespoon of milk. Brush the tops of the cookies with the egg wash.
09 - Bake for 16-18 minutes, or until the edges are lightly golden.
10 - Cool on the baking sheets for 5 minutes, then transfer to a wire rack to cool completely.