Soft-Baked M&M Cookies

Bahan-bahan (30 porsi)

• 2 cups + 2 Tablespoons (265g) all-purpose flour (spooned & leveled)
• 1 teaspoon cornstarch
• 1 teaspoon baking soda
• 1/2 teaspoon salt
• 3/4 cup (12 Tbsp; 170g) unsalted butter, softened to room temperature
• 3/4 cup (150g) packed light or dark brown sugar
• 1/2 cup (100g) granulated sugar
• 1 large egg + 1 egg yolk, at room temperature
• 1 and 1/2 teaspoons pure vanilla extract
• 1 cup (230g) mini M&Ms (plus 2 Tablespoons for topping, optional)