Creme Mousseline

Creme mousseline is pastry cream enriched with whipped butter, beaten in once the cream has cooled to roughly butter temperature. This gives it the silken structure of a buttercream with the flavour of pastry cream, ideal for layered desserts like fraisier and entremets where the filling must hold its shape between fruits and sponge. The trick is temperature matching: butter colder than the cream will leave lumps, butter warmer and the whole thing turns to soup. Aim for both around 20 to 22 Celsius. Flavour with vanilla, praline, pistachio paste or fruit purees, and pipe through a star tip.