Prep time: 40 minutes
Baking time: 10 minutes
Makes 28 cookies
1 cup (2 sticks) unsalted butter, room temperature
1/2 cup granulated sugar
1/4 teaspoon fine salt
1 large egg
1 teaspoon vanilla extract
2 cups all-purpose flour
1/2 cup jarred dulce de leche or other thick caramel filling Coarse or flake sea salt, (preferably Maldon Salt), for sprinkling
1. Preheat the oven to 350. With a mixer, cream together butter, sugar and salt until fluffy and light, 2 to 3 minutes.
2. Beat in egg and vanilla. Add flour, and mix until just incorporated. Divide dough into two equal balls. Flatten into disks, wrap in plastic wrap, and chill until firm, about 1 hour.
3. Generously flour a sheet of parchment paper. Place one disk in center, and dust the top and a rolling pin with flour. Working quickly, roll dough into a thickness just shy of a quarter inch. Slide onto baking sheet, and chill again. Repeat process with second ball of dough.
4. Flour two fluted, round cookie cutters: 1 larger (about 1 inches) and 1 smaller (about 1 inch). Using the larger cutter, cut half of the dough for the bottoms of the cookies. Lift off excess dough to chill, and reroll for more cookies. Re-chill cut cookie bottoms.
5. For cookie tops, use the large cutter on the second half of dough. Then, using the smaller cutter, place in the center of each top to form a hole for the caramel to show through. Re-chill.
6. Line a baking sheet with parchment, and place cookies 1 inch apart. Bake 9 to 11 minutes, rotating after 5 minutes, until just set. Do not brown.
7. Transfer cookies to a rack, and let cool completely. Spread bottom cookies with caramel. Cover with tops. Sprinkle the caramel with sea salt.