Place a medium bowl in a larger bowl of ice water. Set Aside.

Bring milk to the boiling point in a heavy saucepan over medium heat.

Meanwhile, beat egg yolks in a large mixer bowl until smooth. Gradually add 1/3 cup plus 1 tablespoon of sugar and continue berating until the mixture is pale yellow and forms a ribbon when beaters are lifted (about 7 minutes.)

Gradually add boiling milk to yolk mixture, beating constantly to avoid the yolk curdling. Return the mixture to the saucepan, and cook over low heat - stirring with a wooden spoon, for 30 seconds. Immediately pour custard into the bowl set over ice water.

Cool, stirring occasionally.

Beat the butter and praline paste in a large bowl until smooth and creamy. Gradually beat in cooled custard.