Preheat the oven to 350°F (175°C).
Cream together 1 cup of softened unsalted butter, 1 cup of granulated sugar, and 1 cup of packed brown sugar until light and fluffy.
Beat in 2 large eggs one at a time, then stir in 1 teaspoon of vanilla extract.
Whisk together 3 cups of all-purpose flour, 1 teaspoon of baking soda, and 1 teaspoon of salt in a separate bowl.
Combine the dry ingredients with the wet ingredients gradually, mixing until just combined.
Drop rounded tablespoons of dough onto a baking sheet lined with parchment paper, leaving space between them.
Bake in the preheated oven for 10-12 minutes or until the edges are lightly golden.
Cool on the baking sheet for a few minutes before transferring to a wire rack to cool completely.
Decorate your cooled cookies with royal icing, edible glitter, and colorful sprinkles as desired!