1. In a food processor, pulse almonds and flours until nuts are finely ground. Add salt and cinnamon; pulse to combine.

2. In the bowl of a stand mixer fitted with a paddle attachment, beat together butter and sugar on medium speed until smooth and fluffy. Add egg yolk and almond extract; beat until combined. Reduce speed to low; gradually beat in flour mixture until just combined.

3. Preheat oven to 350 degrees. Roll tablespoon-size portions of dough into 1/4-inch-thick ropes, each about 7 inches long. Transfer to parchment-lined baking sheets and shape into hearts. Refrigerate until firm, about 10 minutes.

4. Bake, rotating sheets halfway through, until cookies are golden brown and crisp, about 17 minutes. Let cool completely on baking sheets on wire racks. Dust with confectioners' sugar just before serving.