For preparing butterscotch ice cream, take a heavy bottomed pan and melt in butter, stir in sugar & cook in a low flame, stirring continuously until the sugar begins to caramelize.

Remove from flame, stir in the milk & continue stirring until the caramel has dissolved completely.

Return to flame & stir in the egg yolks gradually.

Cook in a low flame, stirring continuously until the custard is thick enough to coat the back of the spoon.

Remove from flame & keep aside to cool.

Freeze till partially set, beat again & refreeze till firm.