These soft, cake-like treats are like a little key lime pie in cookie form.
Preheat the oven to 350 degrees F (175 degrees C). Grease 2 cookie sheets with cooking spray or line with silicone baking liners.
Combine cream cheese, butter, brown sugar, and white sugar in a mixing bowl. Beat with an electric mixer until light and fluffy. Beat in egg and vanilla extract until smooth. Slowly beat in flour, baking powder, and salt. Fold in white chocolate chips and lime zest.
Drop teaspoonfuls of cookie dough onto the prepared cookie sheets, leaving about 1 inch between each cookie.
Bake in the preheated oven until cookies are set and lightly browned around the edges, 10 to 14 minutes.