- 2 cups sugar
- 2/3 cup water
- 6 egg whites
- pinch of salt
- 1/4 teaspoon cream of tartar
- 5 sticks unsalted butter at room temperature
- 1 Tablespoon pure vanilla extract
Dissolve sugar in water in a heavy saucepan.
Bring to a boil without stirring. Cover and let boil for 3 minutes until no sugar crystals remain.
Uncover and continue boiling until syrup reaches soft ball stage, 240 degrees.
While sugar syrup is cooking, beat egg whites and cream of tartar in a mixer, using a wire whip until very stiff peaks form.
When 240 degrees is reached, pour 1/4 cup of the syrup into the stiffly beaten egg whites, drop by drop, beating at high speed.
Gradually add the rest of the syrup in a fine stream and beat until cool, 7 to 10 minutes.
In a separate bowl, cream butter until fluffy.
When meringue mixture is cool, add the softened butter, 3 Tablespoons at a time. Beat well.
Frosting should get thick and creamy with the addition of the butter.
Meringue must be cool or frosting will remain thin. If this happens, stir over ice until it thickens.
Beat in vanilla. Frosting is now ready to use.
Do not refrigerate.
Keep cool over a bowl of ice water.
Frost and decorate.