While this may sound improbable, I have yet to taste a professionally-made vanilla cake that rivals this White Chocolate Buttercream Frosting, paired with The Best (And Easiest) Cake Ever. The creaminess of the butter perfectly balances the richness of the white chocolate. Top quality butter and chocolate are essential.
WHITE CHOCOLATE BUTTERCREAM
Time: 30 minutes
Enough for 2 1/2 dozen cupcakes, or one 8 or 9-inch, 3-layer round cake
Ingredients
2 cups white sugar
6 large egg whites
1/2 tsp. Kosher salt
1 tsp. vanilla bean paste (if flecks of vanilla seeds are unwanted, use vanilla extract)
4 1/2 sticks good unsalted butter, cut into tablespoons at room temperature
8 ounces top quality, real (not baking) white chocolate, melted and cooled
Food coloring, as desired
Instructions
Bring a large saucepan half-filled with water to a simmer.
Chop the white chocolate and add to a medium-sized metal bowl.
Set the bowl in the simmering water and stir the chocolate continuously with a wooden spoon until melted, which should not take long. Set aside to cool.
Pulse the sugar in a food processor until powdery, about a minute.
Add the sugar, egg whites and salt to a metal KitchenAid bowl. Use a wire whisk to combine by hand.
Set the KitchenAid bowl in the saucepan of simmering water and whisk gently by hand, until the sugar dissolves and becomes translucent, about five minutes. Use an oven mitt over your hand that is holding the bowl during this process.
Affix the KitchenAid bowl to the mixer with the whisk attachment. Add the vanilla and stir at speed #8 until stiff and glossy, about 4 minutes.
Beat in the butter a piece at a time, about five seconds apart. If using food coloring, add slowly and intermittently during this process to ensure that the color is distributed evenly.
Beat in the melted chocolate, scraping down the sides of the bowl.
Remove the bowl from the mixer and beat with a wooden spoon to remove air bubbles.
Notes
Unlike icings that are made with confectioner’s sugar, buttercream frosting will not harden when exposed to air.
I prefer to use buttercream frosting immediately versus storing it in the fridge for future use, because buttercream frosting is only smooth and spreadable at room temperature (this makes sense, given that the main ingredient is butter!). This particular buttercream recipe hardens quickly in the refrigerator. Therefore, if you store the frosting in the fridge, even for a short time, you must allow the entire batch to reach room temperature or else your otherwise-beautifully smooth frosting will be marred with cold chunks.
Frost each layer of cake generously with at least 1/2” of frosting.
I like to cut each cake round in half to allow for additional layers of frosting. Use the longest knife you own, e.g., a bread knife or chef’s knife, to allow for more consistent cuts.
Frost cakes with an offset metal spatula to get perfect swirls.
Place parchment paper below the cake to keep your plate/workspace clean while frosting (remove the parchment after you’re done frosting).
Cake cupcake frosting to the next level with minimal effort by using a pastry bag and tips. Don’t be intimidated by the pastry bag – it is much easier to use than you think. It is also cleaner and faster than frosting by hand.
Tips on transportation:
Put the frosted cake or cupcakes in the coldest part of the fridge for as long as possible. The buttercream hardens nicely in the fridge, which allows it to hold its shape during transportation.
After frosting the layers but before frosting the exterior of the cake, insert a few wooden skewers vertically through the cake layers for added stability. (Cut skewers as required for height.)
Frost the cake on a cardboard baking round (available on Amazon) set on parchment paper, versus frosting the cake directly on the serving dish. The serving dish will not likely allow for proper coverage during transportation (e.g., the dish may be too big for a box or cooler).
I prefer transporting the cake in a Styrofoam cooler, and then plating the cake on location.
Pack extra frosting for touchups on location.
Resource Guide
This recipe was adapted from Food & Wine Magazine, February 2012