In the bowl of a stand mixer, cream melted butter with granulated sugar, and brown sugar. Add in the vanilla and the egg. Continue mixing on low speed until just combined. Don’t over mix.
Divide the dough into 12 equal portions and roll into balls with your hands. Place the dough balls on the baking sheet about 2 inches apart. Bake in two batches if necessary.
Bake 9 - 11 minutes until the cookies are just barely golden. Don’t over bake or they won’t be soft. Let them cool on the pan 2 minutes then transfer to a wire rack to finish cooling completely.