In another, larger mixing bowl, whisk together the melted butter, sugar, and lemon zest. Then stir in the eggs, lemon juice, and vanilla until very well combined.
Cover the dough and place it in the refrigerator for at least two hours, and up to 2 days. Just before you’re ready to bake, preheat the oven to 350°F (180°C) and line two sheet pans with parchment paper.
Use a large cookie scoop to portion the chilled dough and roll into balls. Add to a bowl of granulated sugar and roll to coat. Then add each dough ball to a bowl of powdered sugar and roll again to coat.