(Okay, not a stern rebuke, but "statement of my friend's mild preference" seems sort of anti-climactic, doesn't it?)
And, as it turned out, a different friend of mine had spurred a thread about brown butter over on Facebook and I had filed away the phrase "brown-butter buttercream" for future use. So I decided that if I was going to frost a cake I was going to do it with style.
The first step is to brown the butter, which is a simple matter so long as you're willing to hang around the kitchen stirring occasionally. I recommend hiring a three-year-old to run up and down a step stool and report on the state of the butter every thirty seconds, but you can manage without if necessary. You can do this a day or so ahead, which will give the butter plenty of time to cool.
I also recommend doing this with a stand mixer, but I managed with a hand-held electric mixer and you can, too. It just requires a bit of patience.
The recipe I started from made a vat of frosting. I only needed half to frost a two-layer, nine-inch cake. The rest is in my freezer, awaiting the next bout of cake. The recipe here is half of what I made, but feel free to double it if you are making a huge cake or you want to have a bag of buttercream in your freezer in case of cake emergency.I'm considering adding some melted chocolate when I defrost and re-whip the remaining frosting.
This is a buttercream, so it is not going to be stable in hot weather. This might the best frosting in the history of cake, but it is the wrong frosting for summer. Try a cooked flour frosting instead.
1 1/2 pounds unsalted butter
6 ounces egg whites (4-5 large egg whites, 3/4 cup)
1 1/2 cups sugar
1 Tablespoon vanilla extract
To brown the butter:
In a medium sauce pan, melt the butter over medium heat. Allow the butter to come to a boil. Reduce heat to maintain a simmer. Foam will form and then subside. Butter solids will become visible as white flakes. When the white flakes begin to turn brown, remove the pan from the heat. And pour through a fine sieve into a bowl. I do not line my sieve with cheesecloth or a coffee filter because I want the small bits milk solids to remain. They fleck the frosting with tiny bits of extra deliciousness. Allow the butter to cool to room temperature, then move to the refrigerator, where it will keep well for at least a week.
|Browned butter, scooped into balls for easy incorporation into the frosting. |
That dark brown stuff is the browned milk solids. They're delicious.
On the day you are going to make the frosting, remove the butter from the refrigerator and set aside to soften.
Mix the sugar and egg whites together in a large, heat-proof bowl, then set it over a pan of simmering water. (If you're using a stand mixer, you can just use the mixer's bowl.) Heat, whisking frequently, until the egg whites are 140 F, or hot to the touch.
Remove the bowl of egg whites from the double boiler and set in on the counter on a slightly damp towel to prevent slipping. Using your hand mixer at full-power, beat the eggs into a fluffy meringue until the bowl is cool to the touch. If the meringue is more than room temperature, then the butter will melt and the texture of the frosting will not be as good. If using a stand mixer, beat with the whisk attachment on high speed until the bowl is cool to the touch. You should have a stiff, glossy meringue. It would be a perfectly adequate frosting on its own if you were so inclined.
|Congratulations! You've made marshmallow fluff!|
Add vanilla extract to the meringue. With the beater on high speed, begin incorporating the butter a couple of tablespoons-full at a time, pausing occasionally to scrape down the sides of the bowl with a flexible spatula.
Frosting can be used immediately, stored in the refrigerator for several days, or frozen for several months. Chilled frosting should be allowed to come to room temperature slowly over several hours, and then re-whipped before being used.