Combine melted butter, granulated sugar, and brown sugar in a mixing bowl. Mix until smooth.

Add the egg and vanilla extract to the mixture and beat until well combined.

In a separate bowl, whisk together the flour, baking soda, and salt.

Gradually mix dry ingredients into the wet ingredients until just combined.

Fold in chocolate chips and sprinkles.

Drop spoonfuls of dough onto a prepared baking sheet. Chill in the refrigerator for at least 2 hours.

Preheat oven to 350°F. Bake cookies for 11-15 minutes until golden edges. Cool before serving.