Gluten-Free Almond Alfajores

1 1/2 cups almond flour
1/2 cup potato starch
1 teaspoon gluten-free baking powder
1 pinch ground anise
1 stick unsalted butter, softened
3/4 cup confectioner's sugar, plus more for dusting
2 egg yolks
Juice of 1/4 lemon
1/2 teaspoon vanilla extract
1/2 cup coarsely chopped natural almonds
1 cup of dulce de leche {store bought, gluten-free}

Sift together the almond flour, potato starch, baking powder and anise; set aside.
 Cream the butter and sugar with an electric mixer until light and fluffy. Add egg yolks one at a time; continue to beat. Add lemon juice and vanilla; beat again until light and fluffy. Fold in dry ingredients.
 Turn out dough on a work surface lined with potato starch; use your hands to gently pat dough together. Roll dough into a 2 1/2-inch diameter log.
 Roll the log in chopped almonds; cover in plastic wrap and freeze for 30 to 45 minutes.
 Preheat oven to 350 degrees.
Using a wire cheese cutter or sharp knife, cut dough into 1/4-inch slices. Place 1/2-inch apart on a parchment-lined baking sheet, patting each cookie with your fingers as necessary to ensure it is circular.
 Bake for 15 to 17 minutes, until lightly golden.
Let it cool completely.
 Spoon a generous tablespoon of dulce de leche onto half of the cookies. Create sandwiches with the remaining cookies, gently pressing down.
Dust them with confectioner's sugar.