Domino'S French Buttercream Frosting - cooking recipe

Ingredients

2 cups granulated sugar
1/2 cup water
1/4 teaspoon cream of tartar
1/8 teaspoon salt
4 egg whites
1 cup confectioners' sugar
1 1/2 teaspoons vanilla
4 tablespoons butter, soft

Preparation

Combine granulated sugar, water, cream of tartar and salt in a saucepan; cook and stir until sugar melts.
Cook WITHOUT stirring until syrup reaches 260\u00b0 on candy thermometer; Wash down sugar crystals from side of pan with wet brush.
Beat egg whites until stiff; add syrup slowly; beat 3 min.; on low speed, beat in confectioners' sugar.
Cool; fold in vanilla and butter.
For chocolate frosting: beat in 4 squares of unsweetened baker's chocolate that has been melted and cooled.