In search of the perfect Soft and Chewy Sugar Cookies last year, I really put my dough through its paces. In side-by-side experiments, I tested my recipe with different creaming methods, leavening agents, sugar types, and egg ratios.
I even made a batch with cake flour, a low-protein flour that has the mild flavor of white wheat. It was all wrong for classic sugar cookies, but my tasters kept circling back for another bite long after their notes were complete. "I don't know what it is," they said. "It just tastes so familiar."
As with my Angel Food Cake, the success of this recipe hinges on the unique behavior of bleached cake flour. Unbleached cake flour, cake flour processed with modified starch, cake flour fortified with malted barley, and DIY solutions (like all-purpose flour mixed with cornstarch) simply won't do.
While my version may be more streamlined than the 125-ingredient formula listed on the package, the overall flavor profile is the same, simply reincarnated with real butter and vanilla. It's soft and cakey due to cake flour, but not in a generic sense. Because of the strategic use of egg whites, it tastes like white cake in particular.
If you've read up on my Cookie Science eggsperiments, you may recall that egg whites can be a bit problematic. When you're creaming butter and sugar, their high water content will break the air-and-fat emulsion, resulting in a curdled batter. Improper aeration makes the dough dense, leading to cookies that bake up rather fudgy—obviously, a poor approach to re-creating a Lofthouse Cookie's fluffy crumb.
Happily, I discovered that egg whites won't break the emulsion if they're mixed with a bit of cream to simulate the fat of the yolk. Not only does this allow for proper aeration, the added richness also makes up for the sometimes-crumbly texture of lean whites in a dough. The result is a cookie that's cakey in the best possible way: light and tender, with a rich and velvety crumb.
The finishing touch is a smear of vanilla frosting. Where bleached cake flour is the trick to my cookies, the secret weapon in my frosting is organic powdered sugar. There's a more in-depth article here, but in short: Organic powdered sugars are more likely to be made with tapioca starch, which feels less gritty than cornstarch (the ingredient that causes so many of us to hate powdered-sugar frostings). On the flip side, the raw cane sugar in organic brands will give the frosting an ivory hue, which may run contrary to your ideal of a snowy-white frosting.
In place of butter, I make my frosting with cream. Its liquid content better dissolves the powdered sugar, regardless of what type you choose, for a much creamier frosting. It still crusts over like a traditional American buttercream, so the cookies are just as easy to handle, store, and transport without smushing, yet it melts more readily on the tongue.