Ingredients:

  • 1/2 cup (115g) unsalted butter, softened
  • 3/4 cup (150g) granulated sugar
  • 1 large egg, room temperature
  • 1 tsp (5ml) vanilla extract
  • 1 7/8 cups (235g) all-purpose flour
  • 1/2 tsp (2g) baking powder
  • 1/4 tsp (1.5g) salt
  • 1/2 cup (115g) unsalted butter, softened
  • 2 cups (240g) powdered sugar
  • 1 tbsp (15ml) heavy cream
  • 1 tsp (5ml) vanilla extract
  • 2 tbsp (20g) rainbow sprinkles

Instructions:

  1. Preheat the oven to 325°F (160°C) and line baking sheets with parchment paper or silicone mats.
  2. Beat 1/2 cup (115g) softened unsalted butter and 3/4 cup (150g) granulated sugar on medium-high speed for 2-3 minutes until pale and fluffy.
  3. Add 1 large room temperature egg and 1 tsp (5ml) vanilla extract; beat on medium speed until smooth and fully combined.
  4. Whisk 1 7/8 cups (235g) all-purpose flour, 1/2 tsp (2g) baking powder, and 1/4 tsp (1.5g) salt together in a separate bowl.
  5. Gradually add the dry flour mixture to the wet ingredients on low speed, mixing only until flour streaks disappear.
  6. Scoop rounded tablespoons of dough onto the prepared sheets, spacing them 2 inches apart.
  7. Bake for 10-12 minutes; remove when edges are set but tops remain pale and soft. Let cookies cool completely on the pan.
  8. Beat 1/2 cup (115g) softened unsalted butter until creamy.
  9. Gradually add 2 cups (240g) powdered sugar one cup at a time on low speed, then increase to high for 2 minutes.
  10. Stir in 1 tbsp (15ml) heavy cream and 1 tsp (5ml) vanilla extract until the frosting is velvety and holds a peak.
  11. Apply a generous swirl of buttercream frosting to each cooled cookie using a piping bag or offset spatula.
  12. Immediately press 2 tbsp (20g) rainbow sprinkles into the top of the frosting.