4 egg whites
1 1/4 cups
granulated sugar
1 1/2 cups
unsalted butter, cut into tablespoons, at room temperature
Puree the
strawberries in a food process or blender; set aside.
Combine the
egg whites and sugar in the bowl of a stand mixer set
over a pan of simmering water. Whisk constantly by hand until the mixture reaches 140 F on an instant-read thermometer and the sugar has dissolved (the mixture should feel
completely smooth when rubbed between your fingertips).
Attach the
bowl to the mixer fitted with the whisk attachment. Starting on low and
gradually increasing to medium-high speed, mix until stiff (but not dry) peaks
form. Continue mixing until the mixture is fluffy and glossy, and completely
cool (test by touching the bottom of the bowl), about 10 minutes.
Reduce the
mixer speed to medium-low and add the butter a few tablespoons at a time,
mixing well after each addition. Once all the butter has been added, scrape down
the sides of the bowl with a spatula and switch to the paddle attachment;
continue beating on low speed until all air bubbles are eliminated, about 2
minutes. Add the strawberry puree and beat until combined.
Stir the frosting
with a rubber spatula until the frosting is smooth. Keep the buttercream at
room temperature if using the same day, or transfer to an airtight container
and refrigerate up to 3 days or freeze up to 1 month. Before using, bring to
room temperature and beat with paddle attachment on low speed until smooth
again, about 5 minutes.
Makes enough frosting for 34 cupcakes.
From Brown Eyed Baker blog, originally from Martha Stewart’s Cupcakes