6 large egg yolks
3/4 c sugar
1/2 c corn syrup
2 c softened butter (I actually used 2 tbs less than that)
flavoring (vanilla, melted chocolate, coffee flavoring, almond extract, pistachio or hazelnut paste)
Have ready a greased 1 c heatproof glass measure nearby.
Beat the yolks with an electric mixer until light in color.
Meanwhile, combine the sugar and corn syrup in a (preferably nonstick) saucepan and heat stirring constantly, until the sugar dissolves and the syrup comes to a rolling boil. (If you stop short of that, the buttercream will be too thin.)
Immediately transfer syrup to the glass measure to stop the cooking.
If using an electric hand-held mixer, beat the syrup into the yolks in a steady stream. (Avoid the beaters, because they will spin it to the sides of the bowl.)
Use a spatula to remove the end of the syrup clinging to the glass measure into the mixing bowl. (You will wish you had 2 pairs of hands while doing all this.)
Continue beating until completely cool.
Gradually beat in butter.
Do not despair if it looks very thin in the beginning.
The buttercream will reach the desired consistency toward the end. Beat in flavoring until combined.
This buttercream can be refrigerated or frozen.
To use refrigerated buttercream, wait until it comes to room temperature and re-beat to restore texture.
If you beat it while is cold it will break down and be ruined.
Pairs Well With
Adapted from The Cake Bible