2sticks ( 1 cup) unsalted butter, room temperature
1cup light brown sugar
1/2cup granulated sugar
1large egg, room temperature
1yolk of large egg, room temperature
1teaspoon vanilla extract
1 TBS fresh lime juice
zest of one lime
Line two baking sheets with parchment. Whisk together flour, baking powder, salt and cardamom and set aside.
In a stand mixer fitted with a paddle attachment, stir the butter and sugar together till just combined, about 30 seconds.
Add the egg and egg yolk; stir to combine. Add the vanilla extract, lime juice and lime zest, stir again.
Gently add in the dry ingredients a little at a time, stirring just until they are combined, about 30-45 seconds.
Scoop the dough with a tablespoon and roll into balls. Place evenly on cookie sheets and flatten slightly with the back of a spatula. (If the dough is very soft, it may be easier to do this after the dough is chilled.)
Place the cookie sheets in the refrigerator and chill dough for 30 minutes.
Preheat oven to 375 degrees
Bake for 5 minutes. Reverse cookie sheet front to back. Bake for 5-7 more minutes until cookies are brown on edges and still soft in the center.
Place cookie sheet on wire rack for 5 minutes. Remove cookies with spatula and place them on wire racks to cool completely.