Line baking sheet with parchment paper (I used a round pizza baking sheet, but you can use a rimmed rectangular baking sheet if you don't have a round one).
In a mixing bowl, combine butter and sugar.
Add vanilla and egg and stir.
Stir in flour, cornstarch, salt.
Stir in chocolate chips.
Add corn syrup and mix until well combined.
Spread batter on to lined cookie sheet and bake for 20 minutes. Cookie should be golden brown.
Cool and decorate!
Notes
This recipe is my own, but the addition of corn syrup was inspired by Just a Pinch!This recipe is based on using a 12" round rimmed baking sheet. It can also be made on a quarter sheet pan (usually around 13"x9") but will be a slightly thicker cookie and will need to bake for about 30 minutes.If you are not using Diamond Crystal brand Kosher salt, please scroll up to the measurements section and read about salt measurements. If you are using table salt, you will need to significantly reduce the measurement. After adding flour, mix as little as possible. Just enough to incorporate the remaining ingredients. Over-mixing the flour will result in a too-chewy (not in a good way!) cookie.