Preheat oven to 350°F/175°C and line 2 large cookie sheets with parchment paper or silicone mats. Set aside.
Cream together 1/2 cup (113g) unsalted, softened butter, 2/3 cup (133g) granulated sugar, and 1/3 cup (66g) light brown sugar in a large bowl with an electric hand mixer or stand mixer fitted with a paddle attachment. Mix on a medium-high speed with an electric mixer until the mixture becomes lighter in color (about 2 minutes). It's important that the butter is soft to the touch, otherwise you will have a hard time mixing the dry ingredients into the dough.
Mix in 1 egg (56g), 1 tsp (5g) vanilla extract, and about 1 tsp of red gel food coloring on a medium speed until combined. Scrape the sides and bottom of the bowl as needed with a rubber spatula.
Then mix 2 cups (250g) flour (NOTE: If you're using a cup measure and not a scale, you need to fluff the flour in the bag, spoon it into the measuring cup, then level it with a knife. This is how you properly measure flour when baking, otherwise you'll end up using a lot more than the recipe calls for :) ), 1 Tbsp unsweetened cocoa powder (6g), 1 tsp baking soda (6g), and 1/4 tsp salt (1g) into the wet ingredients on a low speed until combined. It takes a bit of mixing to come together, so if it looks a little dry, keep mixing! The dough should be quite thick once it's ready to be scooped.
Use a 1 1/2 Tbsp cookie scoop or a large spoon to scoop and roll about 21 cookie dough balls.
Roll each cookie dough ball in granulated sugar, then place the cookies about 2 inches apart on the prepared baking sheets. Bake for about 9 minutes, or until the cookies seem set in the center.
I like to gently flatten the cookies with the bottom of a metal measuring cup or glass while they're still warm to give them super chewy centers, but this is optional. Then let the cookies cool on the sheet for 10 minutes, then place them on a wire rack to finish cooling.