Preheat your oven to 350°F (175°C) and prepare two baking sheets lined with parchment paper.

In a spacious bowl, cream together the softened butter, granulated sugar, and brown sugar until light and fluffy.

Crack the eggs into the mixture one by one, then add the vanilla extract, mixing until smooth.

In a separate bowl, whisk together the flour and baking powder. Gradually fold this mixture into the wet ingredients until just combined.

Fold in the rainbow sprinkles gently.

Scoop rounded balls of dough onto the prepared baking sheets, spaced about two inches apart.

Bake for 10-12 minutes until the edges are golden and the centers are soft.

Let cool slightly before transferring to wire racks.