Easy Sugar Cookies with Frosting

Ingredients

• 3/4 cup (170 g) unsalted butter, softened
• 3/4 cup (150 g) granulated sugar
• 1 large egg
• 1 large egg yolk
• 1 teaspoon vanilla extract
• 1/2 teaspoon baking soda
• 1/2 teaspoon cream of tartar
• 1/2 teaspoon salt
• 2 cups (248 g) all-purpose flour
• 4 tablespoons (57 g) unsalted butter, softened
• 1 1/3 cups (151 g) powdered sugar
• 1/8 teaspoon salt
• 1 tablespoon (15 ml) milk
• Food coloring, optional
• Sprinkles, optional