m&m cookie recipe

2 1/4 cups all-purpose flour - 1/2 teaspoon baking soda - 1/2 teaspoon salt - 1 cup unsalted butter, at room temperature - 1 cup packed light brown sugar - 1/2 cup granulated sugar - 2 large eggs - 2 teaspoons vanilla extract - 1 1/2 cups M&M candies - 1 cup semisweet chocolate chips (optional)