01 -
Preheat the oven to 350°F (175°C). Line baking sheets with parchment paper.
02 -
In a large mixing bowl, beat the softened butter, brown sugar, and granulated sugar together until the mixture is pale and creamy. Continue mixing for at least 2 to 3 minutes.
03 -
Beat in the light corn syrup, vanilla extract, and egg until the mixture is just combined. Do not over-mix.
04 -
Sift in the all-purpose flour, baking soda, and salt. Mix until a soft, pliable dough forms. If the dough is too sticky, add extra flour one tablespoon at a time until manageable.
05 -
Gently fold in half of the chocolate chips and half of the M&M's using a spatula or your hands, mixing only until distributed throughout the dough.
06 -
Scoop dough into balls using a 1 tablespoon-size cookie scoop for standard cookies (yielding 18 to 20 cookies), or 2 tablespoon portions for jumbo cookies (yielding about 12). Place dough balls at least 3 inches apart on the prepared baking sheets.
07 -
Press the remaining M&M's and chocolate chips onto the tops of each cookie dough ball.
08 -
Bake cookies in the preheated oven for 11–12 minutes, until edges turn golden but centers appear puffy and underdone. Do not overbake.
09 -
Remove baking sheets from the oven and tap them lightly on the counter to help flatten the cookies. Allow cookies to cool on sheets for 30 minutes before transferring to a wire rack.