01 - Preheat oven to 325°F. Line two baking sheets with parchment paper.
02 - Whisk together all-purpose flour, almond flour, baking powder, and salt in a medium bowl until thoroughly blended.
03 - Beat softened butter and granulated sugar in a large bowl until light and fluffy, approximately 2-3 minutes.
04 - Mix in egg (reserving half the yolk for egg wash), almond extract, and vanilla extract until fully incorporated.
05 - Gradually fold dry ingredients into wet mixture, mixing just until a soft dough comes together. Avoid overmixing.
06 - Scoop tablespoon-sized portions, roll into balls, and arrange 2 inches apart on prepared baking sheets. Flatten slightly and press a blanched almond into the center of each.
07 - Whisk reserved egg yolk with 1 tablespoon milk. Brush tops of cookies with mixture using a pastry brush.
08 - Bake for 16-18 minutes until edges are lightly golden. Cool on baking sheets for 5 minutes before transferring to wire rack.