Preheat the oven to 350°F. Line the baking sheet with parchment paper.

Combine the sugars and butter. You can also use an electric mixer and beat them together with the paddle attachment for 1 to 2 minutes or until light and fluffy.

Whisk in the egg.

Pour in the milk and mix.

Slowly add in the flour. Mix until just combined.

Stir in the food coloring.

Fold in the chocolate chips and marshmallows.

Portion the dough into 6 to 10 pieces, depending on your preferred cookie size. Press a piece of chocolate into the center of each one.

Form the dough into a ball to cover the chocolate. Refrigerate for 2 hours.

Transfer the cookies to a baking sheet and bake for 12 to 15 minutes or until the edges look set.

Cool the Cookie Monster cookies on the baking sheet for 5 to 10 minutes, then transfer to a wire rack to finish cooling.