Preheat oven to 350 degrees F.
In a large bowl, with an electric mixer, cream butter and sugar until fluffy. Add the eggs 1 at a time and the lime juice, and mix well. In separate bowl, combine flour, baking powder and salt. Gradually add the flour mixture to butter mixture until incorporated. Dough should be stiff but not dry. Shape into 1-inch balls, press thumb into center of balls to make an indentation, being careful not to press through to the bottom. Fill indentations with about 1 tablespoon Key lime curd. Bake for 15 minutes, until lightly brown. Transfer to a wire rack to cool. Sprinkle with powdered sugar.
This recipe was created by a contestant during a cooking competition. It has not been tested for home use.