01 - Preheat oven to 350°F. Line two baking sheets with parchment paper.
02 - Beat butter and granulated sugar in large bowl until light and fluffy.
03 - Mix in egg yolk and vanilla extract until fully combined.
04 - Add flour and salt; mix until soft dough forms. Cover and refrigerate 15 minutes.
05 - Combine almond flour, sugar, egg white, and almond extract in medium bowl. Stir until smooth and thick.
06 - Divide dough into 24 equal portions. Roll each into ball, then flatten into 2-inch rounds.
07 - Place 1/2 tsp almond filling in center of each round. Fold and pinch dough around filling to seal, shaping into crescents.
08 - Gently press each crescent into sliced almonds to coat top.
09 - Place cookies 1 inch apart on prepared baking sheets.
10 - Bake 13-15 minutes until edges are golden brown.
11 - Let cookies rest on baking sheet for 5 minutes.
12 - Transfer to wire rack. Once completely cool, dust lightly with powdered sugar.