Lemon Lime Basil Shortbread Cookies

I am hoping I have enough fresh basil left when it finally cools off and I can try these cookies.  I am currently battling with Japanese beetles to save my basil crop.  OK, crop might be a stretch but I need a little basil left and those bloody beetles are turning my basil leaves into lace.  They are not too appetizing that way.

1 C. all purpose flour
1/2 C. powdered sugar plus more for  pressing cookies
1/2 C. chilled, unsalted butter, cut into 1/2 inch cubes
2 tbsp. sliced fresh basil leaves
1 tsp. finely grated lemon zest plus 1 tbsp. fresh lemon juice
1/2 tsp. finely grated lime zest
1/4 tsp. kosher salt
Sanding sugar (optional)

Preheat oven to 375 degrees.  Place flour, 1/2 C. powdered sugar, butter, basil, both zests, lemon juice and salt in a food processor.  Pulse until large moist clumps form.  Measure level teaspoons of dough, roll between your palms to form balls.  Place on a large baking sheet, spacing 2" apart.  Lightly dust the bottom of a flat measuring cup with powdered sugar and press cookies into 2 inch rounds, dusting the cup bottom with powdered sugar as needed to prevent sticking.  Sprinkle tops of cookies with sanding sugar, if desired.

Bake until edges are brown, about 20 minutes.  Transfer to a wire rack; let cool.