Lemon Cake

method

  1. 1. Place the egg whites and sugar in a metal bowl and set over a saucepan filled with 2 inches (5 cm) of gently simmering water. Whisk constantly (but not vigorously) until the mixture reaches 150°F (65°C) on a candy thermometer, about 6 minutes.
  2.  Use electric beaters or transfer the mixture to the bowl of a stand mixer fitted with the whip attachment and whip at high speed until the meringue has cooled to room temperature (it will hold a stiff peak by then).
  3.  With the mixer running at high speed, add the butter a few pieces at a time. At first the meringue will hold its volume, then the buttercream will deflate a little and become very creamy yet fluffy looking. Beat in the vanilla. Use immediately, or cover and chill or freeze for later use.
  4.  To use the frosting once it’s been chilled, let it come to room temperature on the counter. Rewhip the buttercream to make it fluffy and spreadable.