- 3 whole eggs
- 3 egg yolks
- 1 cup granulated sugar
- 1/2 cup plus 2 tablespoons corn syrup
- 6 ounces bittersweet chocolate, melted
- 1 pound unsalted butter (4 sticks) at room temperature
- 2 teaspoons vanilla extract
In the bowl of a standing mixer, beat the eggs and egg yolks until light and fluffly and doubled in size.
Combine the sugar and corn syrup in a small saucepan over medium heat, stirring constantly until the sugar dissolves and they syrup comes to a rolling boil. Transfer the syrup to a heat proof bowl or measuring cup to stop the cooking.
Pour a small amount of the syrup into the egg yolks begin beating with the paddle attachment on low speed. Pour the remaining corn syrup into the egg mixture in a slow, steady stream. Continue beating until the completely cool and fluffy, about 5 minutes. Gradually beat in the chocolate, butter and vanilla until the icing is is light and fluffy, about 3 minutes.
Use immediately or cover and refrigerate for up to 1 week. Let the buttercream come to room temperature before using.