The Sub: Used 3/4 cup in place of each cup of sugar in the classic recipe (see Note about using liquid sweeteners below).
The Verdict: Corn syrup gave us a beautiful cookie—darker at the edges and a lighter golden in the middle. But while they looked good, these cookies were lacking in sweetness and overall flavor. Tasters picked up salty undertones (possibly due to the lack of sweetness) and some noticed a sour aftertaste. We don’t recommend using 100% corn syrup in place of granulated sugar and/or brown sugar in cookies.
*Note: When using a liquid sweetener, in place of granulated white and/or brown sugar, reduce liquids in the recipe by 2 tablespoons for each cup of sugar swapped. (In our testing, we eliminated 1 of the 2 eggs called for in the classic chocolate chip recipe.) And reduce oven temperature by 25°F.