I’m big on cookies, so much so that I consider them pantry staples. Can you even consider them pantry staples? That’s a debate for another day. But a cookie or three with afternoon tea is simply nonnegotiable.
If we were to sort cookies by texture, we could drop them into crisp like shortbread, chewy like oatmeal cookies, and smooth like Yo-Yos. Then we’ve got combo textures—chocolate chip cookies fall into this group.
Like a family cornbread recipe, chocolate chip cookies are highly personal. Some folks love them crispy, others prefer chewy, and others still like a mix (I like a mix).
Today, we’re making chocolate chip cookies that aren’t quite crispy, or chewy, or crispy-chewy. Thanks to a couple special ingredients—and science!—these new-fashioned cookies will melt in your mouth at first bite.
What Decides the Textural Fate of a Cookie?
It’s all about the ingredients and their ratios.
Most grain-based cookie recipes contain fat (like butter or shortening), sugar (say granulated or brown), flour (usually wheat), some kind of leavening agent (such as baking soda or baking powder, and in some instances both), a liquid binding agent (maybe milk), and sometimes eggs. Other ingredients focus on flavor (think vanilla or citrus zest) and texture (like chewy dried fruit or crunchy toasted nuts).
To make chocolate chip cookies with a singular, melt-in-your-mouth texture, we’ll need a couple ingredients that aren’t found in traditional recipes: custard powder and confectioners’ sugar. Let’s break them down one by one.
Custard powder, as it is known in the U.K. and the rest of the Commonwealth nations, is primarily cornstarch with food coloring and flavorings like vanilla. In America, custard powder isn’t readily available in supermarkets, but another, almost identical product is: instant pudding mix. It is important to note that most brands of instant pudding in America contain added sugar, which will make your cookies taste sweeter.
In the U.K., custards are viscous sweet sauces. You will see them in desserts like trifles (layers of custard between cake and or fruit). Meanwhile, British puddings refer to sweets like cakes and tarts but also savory dishes, from Yorkshire pudding to black pudding. In America, pudding also refers to a range of dishes, from rice to bread, but pudding itself indicates a spoonable custard. (Learn more about British puddings and desserts at Project Britain.)
When custard powder is mixed with cold milk and heated, the cornstarch thickens (a process called gelatinization), binding with water and forming a gel. This gel transforms the milk into custard. There are a variety of custard powders and instant pudding mixes to choose from: Bird’s is popular in the U.K. I grew up eating Brown & Polson in India. And in America, we’ve got Jell-O and Dr. Oetker. You could also simply use cornstarch to thicken milk, and flavor the custard any way your heart desires.
But what if you use custard powder for something other than custard? Or instant pudding mix for something other than instant pudding?
In cookies, cornstarch (and in turn custard powder and instant pudding mix) does something special. It reduces the amount of gluten formation by nestling itself between the flour particles. This is a good thing, because too much gluten development in a cookie will make it tough and unpleasant to eat. Cornstarch also gelatinizes with the water present in the dough as the cookie bakes, leading to that tender, melt-in-your-mouth texture.
Typically we use granulated, superfine, or caster sugar for baking. But if you swap in confectioners’ sugar (aka powdered or icing sugar), the cookie’s texture will completely change.
Sugar does a few things in cookies. Besides adding sweetness, it prevents gluten formation and absorbs water from the dough and air. The sugar’s texture also affects the cookie’s texture.
The sugar particles’ size influences how fast they dissolve in the cookie batter. Large sugar crystals dissolve less quickly and leave behind large crystals, while confectioners’ sugar will dissolve rapidly and leave behind no visible traces of crystallization.
Of course, all of this depends on the ratio of the other ingredients in the recipe. Take for instance some of the cookies most of us are familiar with. If you make gingerbread cookies with granulated sugar, you can see those large crystals in the finished product because they don’t dissolve as well. In a chocolate chip cookie made with superfine sugar, you won’t necessarily see the crystals with your eyes, but because superfine sugar is made up of small crystals, you will notice how it contributes to a firm crispy or chewy texture.
Confectioners’ sugar takes it one step further. It’s made by grinding white sugar crystals. Because the particles are so tiny, they dissolve fast. They also occupy a smaller space between the flour and other ingredients in the cookie dough. In turn, the cookie dissolves faster in our mouths, tasting much smoother. Irish shortbread, for example, uses both confectioners’ sugar and a little bit of rice flour (a source of starch) to create that signature crumbly texture.
Confectioners’ sugar often contains anticaking agents, like cornstarch, to prevent the sugar from absorbing moisture and clumping. This additional cornstarch will also contribute to the cookie's incredible texture.
Your New Favorite Chocolate Chip Cookie
Now let’s put the science behind cornstarch and confectioners’ sugar to work in a new, deliciously smooth take on the chocolate chip. Unlike the classic crispy-chewy texture, this cookie melts in every bite, leaving behind bits of bittersweet chocolate. Good luck eating just one.