Stained-Glass Sugar Cookies

INGREDIENTS

• 3 cups all-purpose flour (spooned and leveled), plus more for rolling
• 3/4 teaspoon baking powder
• 1/4 teaspoon fine salt
• 1 cup (2 sticks) unsalted butter, room temperature
• 1 1/4 cups sugar
• 4 large egg yolks
• 1 tablespoon pure vanilla extract
• Very finely crushed hard candy, such as Jolly Rancher, in various colors (1 cup total)