1 1/4 c. all-purpose flour, plus more for surface
1 tsp. baking powder
1/2 tsp. baking soda
1/2 tsp. kosher salt
12 tbsp. butter, softened
3/4 c. granulated sugar
Zest of 1 lemon
3 large egg yolks
1 tsp. pure vanilla extract
1 (15.8-oz.) jar dulce de leche
1/4 c. shredded coconut
Preheat oven to 350° and line 2 large baking sheets with parchment. In a large bowl, whisk together cornstarch, flour, baking powder, baking soda, and salt. In another large bowl, using a hand mixer, beat butter, sugar, and lemon zest together. Add egg yolks and vanilla and beat until combined. Add dry ingredients and beat until dough comes together. You should be able to squeeze the dough and it holds together at this point. Lightly flour surface and dump dough onto counter. Form into a smooth ball, then divide in half. Working with one half at a time, roll dough out to ¼” thick. Use a 2 ¼” round cookie cutter to cut out dough and place on prepared baking sheet. Repeat with second half of dough. Gather scraps and shape back into a smooth ball, then re-roll and cut out rounds. Place sheet trays in freezer until dough is frozen, at least 15 minutes. Bake frozen dough for 8 minutes, cookies will still be a little soft and won’t have gained much color. Let cool completely. Flip half of the cooled cookies over and spread with dulce de leche. Top with remaining cookies. Roll the sides in shredded coconut.