Dulce De Leche Bat Cookies
- Whisk together flour, cocoa, salt, and baking powder. Beat butter and sugars with a mixer on medium speed until pale and fluffy. Beat in egg, yolk, chocolate, and vanilla. Reduce speed to low. Add flour mixture, and beat until just combined. Shape into a disk, wrap in plastic, and refrigerate 1 hour.
- On a lightly floured surface, roll out dough to 1/8 inch thick. Cut out 36 rounds with a 2-inch cutter, and space 1 inch apart on parchment-lined baking sheets. Using an aspic cutter set, cut a triangle, point side up, in the center of half the cookies, and then use the half-moon cutter to make one "wing" on each side of the triangle. Refrigerate 30 minutes.
- Preheat oven to 375. Bake until set, 7 to 9 minutes. Let cool. Top each uncut cookie with 1 teaspoon dulce de leche and a cutout cookie.