Preheat your oven to 375°F (190°C).
In a large bowl, use an electric mixer to cream together the softened butter, granulated sugar, and brown sugar until light and fluffy.
1/2 cup unsalted butter, 1/2 cup granulated sugar, 1/2 cup light brown sugar
Beat in the egg and vanilla extract until well combined.
1 large egg, 1 teaspoon vanilla extract
In a separate bowl, whisk together the flour, baking soda, and salt.
1 1/2 cups all-purpose flour, 1 teaspoon baking soda, 1/2 teaspoon salt
Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Be careful not to overmix.
1 1/2 cups all-purpose flour, 1 teaspoon baking soda, 1/2 teaspoon salt, 1/2 cup unsalted butter, 1/2 cup granulated sugar, 1/2 cup light brown sugar, 1 large egg, 1 teaspoon vanilla extract
Fold in the M&M's.
1 cup M&M's
Drop rounded tablespoons of dough onto ungreased baking sheets, leaving about 2 inches between cookies.
Bake for 9-11 minutes, or until the edges are golden brown and the centers are still slightly soft.
Let the cookies cool on the baking sheets for a few minutes before transferring them to a wire rack to cool completely.
Enjoy your delicious BEST M&M Cookies!
