Easy and Chewy Sprinkle Sugar Cookies

0 Preheat your oven to 350°F and line 2 cookie sheets with parchment paper.
1 In the bowl of a stand mixer fitted with the paddle attachment, cream the softened butter and granulated sugar at medium-high speed for about 1 1/2 minutes. Add the vanilla extract, then beat in the whole egg and egg yolk until smooth.
2 In a separate medium bowl, whisk together the dry ingredients: all-purpose flour, baking powder, baking soda, and salt. 
3 Gradually add the dry ingredients to the wet mixture, mixing at low speed until combined. Avoid overmixing for soft sugar cookies. Fold in the sprinkles gently to keep them from breaking.
4 Use a cookie scoop to form cookie dough balls, about 3 tablespoons each. If the dough is very soft and sticky, chill it for 15 minutes. If desired, roll in a bowl of your choice of sprinkles or simply sprinkle with a few on top. I used jimmies mixed in the dough, and a mix of jimmies and nonpareils to sprinkle on top before baking.
5 Place the dough balls on the prepared baking sheets, spacing them 2.5 inches apart. Bake cookies in the lower thirds of the oven for 10-15 minutes. The edges should be set, but the centers will remain slightly soft. Let the baked cookies cool on the cookie sheet for 5 minutes before transferring them to a wire rack to cool completely.