Cream together softened butter and sugar in a mixing bowl until the mixture is light and fluffy, with a pale color and smooth texture.
Add the egg yolks and lime zest to the creamed mixture, then beat again until well incorporated and fragrant.
In a separate bowl, whisk together flour, baking powder, and salt to distribute evenly.
Gradually add the dry ingredients to the wet mixture, mixing on low speed or folding until just combined and the dough begins to come together.
Shape the dough into small balls, about one tablespoon each, and place them on a parchment-lined baking sheet, spacing them apart.
Flatten each ball slightly with the bottom of a glass or your fingers to prevent puffing during baking.
Bake in a preheated oven at 350°F (175°C) for about 12 minutes, or until the edges are golden brown and the cookies are set.
Remove the cookies from the oven and let them cool on the baking sheet for a few minutes to firm up.
Transfer the cookies to a cooling rack and allow them to cool completely before serving, revealing crisp edges and chewy centers.
