Preheat oven to 350 degrees.
Line 2 large baking sheets with a silicon mat or parchment paper. Set aside.
In a medium bowl, whisk together the flour, cocoa powder, baking soda and cornstarch, set aside.
Using mixer, mix together the butter and sugars together for 1-2 minutes, or until sugar dissolves into the butter.
Lower the speed to medium-low and mix in the eggs, red food coloring and vanilla.
Gradually add in the flour mixture, beating until a flour remains.
If adding chocolate chips, fold in chocolate chips with rubber spatula.
Using a ¼ cup, large cookie scoop or ice cream scoop, scoop dough and place on prepared baking sheet, spacing 2 inches apart. You should get jumbo 10-12 cookies. Cookies will bake thick.
Bake cookies for 17 minutes, or until cookies are soft to the touch. When in doubt, take cookies out early, as they will continue to cook as they cool.
Remove from baking sheet after 3-5 minutes and continue to cool on wire rack, then serve as is or with Marshmallow Frosting!