Preheat your oven to 350°F (175°C) to ensure it's hot enough for baking.
In a large mixing bowl, use an electric mixer to cream together the softened unsalted butter, brown sugar, and granulated sugar until light and fluffy.
Beat in the eggs one at a time, followed by the vanilla extract. Mix until combined.
In a separate bowl, whisk together the all-purpose flour, baking soda, and salt. Gradually add this mixture to the wet ingredients, mixing until just combined.
Gently fold in the semi-sweet chocolate chips and rainbow sprinkles into the cookie dough.
Using a cookie scoop or tablespoon, drop rounded balls of dough onto the prepared baking sheet, ensuring they're spaced about 2 inches apart.
Bake in the preheated oven for 10-12 minutes, or until the edges are lightly golden but the centers are still soft. Remove from the oven and let them cool on the baking sheet for a few minutes before transferring them to a cooling rack.
Once the cookies are completely cooled, scoop a generous amount of vanilla ice cream onto the flat side of one cookie. Top with another cookie, pressing down gently to create a sandwich. Roll the edges in additional rainbow sprinkles for an extra festive touch.
