Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.
In a large mixing bowl, cream together the softened butter, granulated sugar, and brown sugar until light and fluffy. This usually takes about 2-3 minutes.
Add in the eggs one at a time, mixing until fully incorporated, followed by the vanilla extract.
In a separate bowl, whisk together the flour, baking soda, and salt. Gradually add this dry mixture to the wet ingredients and mix until just combined.
Fold in the rainbow sprinkles and white chocolate chips until evenly distributed throughout the dough.
Using a cookie scoop or tablespoon, drop rounded balls of dough onto the prepared baking sheet, spacing them about 2 inches apart.
Gently press a few additional sprinkles on the tops of each cookie for added color and texture.
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 the cookies cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.
Notes
For extra fun, add more sprinkles on top before baking.