Preheat oven to 375 degrees. In a stand mixer or with a handheld mixer cream together butter brown and white sugar until light and fluffy.
Add in the egg, vanilla, and yogurt and mix well.
In a medium bowl, whisk together flour, baking soda, lime zest, and salt. Slowly add the dry mixture to the creamed mixture. Mixing until all dry ingredients are incorporated.
Stir in the white chocolate chips and pistachios.
Scoop the dough onto baking sheets lined with parchment paper using a small ice cream scoop.
Bake cookies in preheated oven for about 10 minutes or until beginning to brown.
Remove from oven and allow to cool completely before removing from tray.
Combine the powdered sugar, lime juice, and zest mixing until smooth. Add more lime juice to achieve the desired consistency.
Frost cooled cookies and garnish with extra pistachios and lime zest if desired.