If you offer me anything with frosting, make it buttercream. I’m not talking about cloying versions that use powdered sugar, shortening or both for ease and stability. I want European-style buttercream, made of gently heated sugar and egg whites, whipped until airy and slowly enriched with butter. The richness balances the sweetness, and the fat ensures lightness and loft.
Buttercream welcomes endless color-imparting flavors, from vanilla bean seeds or ground espresso beans to shaved chocolate. I often use Herb-Infused Sugar, choosing lilac or lavender blossoms for pale purple or basil for leafy green frosting to pipe onto Buttery Jam-Filled Cupcakes.
An improvised double boiler safely cooks the egg whites into soft meringue. An instant-read thermometer ensures you’ve hit the target temperature. You can also tell the mixture is ready when it smells like cooked eggs and you can barely stand to stick your finger into it.
A stand mixer works best for the long whipping time. A handheld electric mixer might make your arm a little tired – but not nearly as sore as using a whisk. Make sure the mixer can run for at least 10 minutes without overheating, which rules out most immersion blenders.
Buttercream keeps well, with plastic wrap pressed to its surface, in an airtight container for up to two weeks in the refrigerator and longer in the freezer, but it’s easiest to work with when returned to room temperature and freshly whipped. Transfer it to a piping bag fitted with a decorative nozzle to fill the tops of cupcakes or enhance a larger cake. It also spreads well between cake layers or, with practice, on the top and sides.
This recipe makes enough buttercream to pipe onto 12 cupcakes. To completely cover a 9-inch layer cake, make a double batch.
Basil Buttercream Frosting
Makes about 2-1/2 cups
1/3 cup fresh basil leaves (about 1/2 tablespoon chopped)
1/2 cup granulated sugar
2 egg whites
1 cup unsalted butter at room temperature
1/4 teaspoon sea salt
In a food processor or mortar with a pestle, grind the basil leaves as small as possible. In a small bowl, combine the sugar and basil, pressing with the back of a spoon until the leaves release their oils. Return the sugar mixture to the processor or mortar and pulse or crush until finely ground.
Set a metal bowl over a pot of simmering water that doesn’t touch the bowl’s bottom. Combine the egg whites and basil sugar in the bowl and cook, stirring and scraping with a spatula, for eight to 10 minutes, until the mixture holds steady at 160°F. Remove the bowl from the heat.
With an electric mixer on medium-high speed, whip the mixture for about 10 minutes, until glossy, thick and cooled to room temperature. Lower to medium speed and add the butter a tablespoon at a time, scraping down the bowl as needed, until fully incorporated. Scrape down the bowl again and add the salt. Increase to high speed and whip for about 90 seconds, until fluffy.
Julie Laing is a Bigfork-based cookbook author and food blogger. Learn more about this month’s grilling and camp-meal workshops at TwiceAsTasty.com.