Lately, I've been craving peanut butter like nobody's business. Maybe it's the changing of the seasons, with cooler weather pushing me toward heartier fare, or perhaps it's the fact that I've been baking banana bread nonstop for the better part of a month and I'm powerless to resist the culinary super-couple Peanut Butter and Banana.
Whatever the case, the thing about a craving is that it's meant to be satisfied now, ruling out any dessert that requires a substantial amount of prep, like peanut butter cookies, cake, or ice cream. No, the best and fastest way to peanut-butter-ify something ASAP is with frosting, which can turn a package of graham crackers into a midnight snack, and make cupcakes out of yesterday's banana muffins.
While my cheffy side is inclined toward silky, egg-based European buttercreams, like French and Swiss, when time is short there's something to be said for a quick 'n dirty American buttercream—a simple combination of whipped butter and powdered sugar. Or, in this case, butter and peanut butter. In a previous life, powdered-sugar frostings were a deal-breaker for me, but the discovery of organic, tapioca-based powdered sugar changed my tune.
You can read the full breakdown here, but long story short: Because organic powdered sugar starts with raw cane sugar, it retains more of its natural molasses-y components. That complexity helps organic powdered sugar taste less sweet than its conventional counterparts, which are made from pure sucrose. Due to the scarcity of organic cornstarch, most organic brands start with organic tapioca starch instead. It's not the organic part that matters, but the fact that tapioca starch is finer in texture, and thus silkier on the tongue.
Another way to mitigate the inherent grittiness of raw powdered sugar is to simply use less. That can be something of a trick to pull off with traditional American buttercream, which can turn droopy and soft without sufficient powdered sugar for structure. But a frosting made with butter and peanut butter is thicker and more stable than one made with butter alone, so peanut butter frosting relies on powdered sugar for sweetness more than structure. For that reason, my recipe includes a few spoonfuls of honey to reduce the need for powdered sugar.
Not only is honey peanut butter's best friend, it adds aroma and complexity of flavor, upgrades that further tame the sweetness typically associated with American frostings. If honey's not your thing, just grab whatever sort of liquid sugar you have on hand, whether that's maple syrup, agave, molasses, or plain corn syrup. In fact, even my Homemade Caramel Sauce will get the job done!
Putting it all together is child's play. Mix butter, peanut butter, and honey together (along with a generous dash of salt and vanilla) until creamy and smooth, then sprinkle in the powdered sugar. Taking it slow helps to eliminate the risk of forming those tiny lumps that are all but invisible, though readily apparent on the tongue.
After the powdered sugar has been incorporated, it's vital to beat the whole thing until it's fluffy and light. As with creaming butter and sugar for a cookie dough, you don't want to rush the process. If it's not properly whipped, the peanut butter frosting turns out quite a bit denser, making it seem grittier than if it were properly "diluted" with air.
Check it out. Here's the frosting after the powdered sugar has been incorporated, but with only a minute of creaming.
It seems perfectly creamy and light when you have nothing to compare it to, but four minutes later, it's a totally different sort of thing. Fluffy, pale, and more wonderfully smooth.
As with making a cookie dough or cake batter, it's a good idea to pause and scrape down the bowl and beater about halfway through. This ensures that the consistency is uniform throughout, with no streaks of honey or lumps of powdered sugar.
Even if you don't dream of turning banana muffins into cupcakes, having a quick (and easily customizable) recipe for peanut butter frosting comes in handy whenever you need to pull together an impromptu dessert—or upgrade an existing one. As a salty-sweet brownie frosting, this recipe is a great way to improve a batch that's slightly over-baked or made from less-than-top-notch chocolate. And, of course, it's nothing but glorious overkill on a recipe you already love.