Hazelnut praline dacquoise

Separate the eggs. Measure out 125 g whites for the biscuits and 50 g yolks for the cream by weight. Whisk the yolks with 20 g sugar and 25 g cornflour. Bring the milk to the boil, gradually whisk into the yolks and return to the pan. Boil for 2 minutes, whisking. Spread in a dish, cover the surface and cool for about 30 minutes, then refrigerate until fully cold.

Heat the oven to 150 °C. Spread the ground hazelnuts on one tray and the whole nuts on another. Toast for about 10 minutes, stirring halfway through, without browning deeply. Cool, then roughly chop the whole nuts.

Set the oven to 180 °C. Whisk the reserved whites to firm peaks, gradually adding the remaining 50 g sugar. Gently fold in the cooled ground hazelnuts, 110 g icing sugar and remaining 20 g cornflour. Pipe 2 discs measuring 18 cm onto baking paper. Bake for about 12 minutes until lightly golden. Slide the paper onto a rack and cool.

Let the butter soften. Beat the softened butter. Add the praline paste, then the smoothed pastry cream at a similar temperature to the butter. Whisk for about 10 minutes until smooth and aerated. Fill a piping bag.

Peel the paper from the cold biscuits. Put one disc on a plate and pipe the cream around the edge and over the centre. Scatter the chopped nuts into the cream. Chill for 20 minutes to firm the filling. Add the second disc without crushing the cream and dust with the reserved 10 g icing sugar.