Preheat oven to 350° F.
Line a baking sheet with parchment paper. In the bowl of your stand mixer, beat butter, sugar, and eggs until creamy and smooth.
Add lime zest, lime juice and salt. Mix until just combined.
Shape dough into 1-inch balls and place 1 inch apart on the lined cookie sheet (12 at a time). Dip your thumb in flour then press your thumb into each cookie dough ball, creating an indention.
Bake for 18-20 minutes or until cookies are light golden in color. Remove from the oven and fill each indention with lemon curd. Place bake in the oven for 2 more minutes, allowing the lemon curd to firm up. Remove from cookie sheet and place on a wire rack to cool.