Funfetti Skillet Cookie
- 1/2 cup unsalted butter softened
- 3/4 cup granulated sugar
- 1 large egg
- 1 egg yolk
- 2 teaspoons vanilla extract
- 1 1/2 cups all-purpose flour
- 1/4 teaspoon salt
- 1 teaspoon baking powder
- 1/2 teaspoon baking soda
- 1 1/2 teaspoons cornstarch
- 2/3 cup white chocolate chips
- 1/2 cup rainbow sprinkles