Step 1

Combine egg whites, sugar, and salt in the heatproof bowl of a standing mixer set over a pan of simmering water. Whisk constantly by hand until mixture is warm to the touch and sugar has dissolved (the mixture should feel completely smooth when rubbed between your fingertips).

Step 2

Attach the bowl to the mixer fitted with the whisk attachment. Starting on low and gradually to medium-high speed, whisk 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.

Step 3

Put mixer on medium-low speed, add the butter a few tablespoons at a time, mixing well after each addition. Continue mixing until the mixture emulsifies and comes together in a beautiful, creamy texture. Note: Do not panic if the mixture looks curdled or soupy at any point. KEEP MIXING! It will come together.

Step 4

Juice 1/2 a basket of fresh ripe strawberries in an electric juicer. This is my secret step. It's what makes an ultra pure, smooth buttercream.

Step 5

Add fresh strawberry juice and mix on medium low with whisk attachment until fully incorporated. This may take up to 5 minutes and the buttercream may look curdled at some point. Keep mixing! Or add flavorings or extract of your choice instead of strawberry juice and mix thoroughly.

Step 6

Keep buttercream at room temperature if using the same day. After it sits for a while you may get air bubbles in it. Switch to the paddle attachment, and beat on low speed until all air bubbles are eliminated, about 2 minutes.

Step 7

Store in fridge for up to a week or freeze for up to a month. To use set out and let it come back to room temperature. Let it get very soft before stirring it. If you try to stir it while it's still too cool it will break and you will need to re whip it.