Preheat the oven to 350°F (175°C) and prepare a baking sheet.

In a mixing bowl, combine softened unsalted butter and granulated sugar. Beat until light and fluffy, about 2-3 minutes.

Add the egg and vanilla extract. Mix until fully incorporated.

Whisk together baking soda, baking powder, and all-purpose flour in a separate bowl. Gradually add this to wet ingredients until just incorporated.

Scoop 1½ tablespoons of cookie dough, roll into balls, and coat in colorful sprinkles.

Place the dough balls on the baking sheet, spaced two inches apart.

Bake for 10 minutes until set and lightly golden around the edges, keeping the center soft.

Allow to cool on the baking sheet for 8-10 minutes, then transfer to a wire rack to cool completely.