Step 1

Lightly grease 2 baking trays with butter. Roll out the puff pastry on a lightly floured work surface to a 45cm x 25cm rectangle. Cut out two discs, one measuring 20cm, the other 25cm in diameter (see Debbie’s tips). Transfer to the trays, then chill for 20 minutes.

Step 2

For the almond paste, cream the butter and sugar together in a bowl until pale and fluffy. Beat in the egg and one of the yolks, then stir in the ground almonds, flour and rum.

Step 3

Remove the pastry discs from the fridge. Spoon the almond paste onto the smaller disc and spread out with a palette knife, leaving a 2.5cm border around the edge and mounding it up in the centre.

Step 4

Beat the remaining yolk with 1 tsp cold water, then brush a little around the pastry border. Lay the second disc over the filling and press the edges together to seal, smoothing out any trapped air. Crimp the edges between your thumb and forefinger (see food team’s tip). Use the tip of a sharp knife to make a small hole in the centre for the steam to escape, then chill for 20 minutes.

Step 5

Meanwhile, heat the oven to 220°C/200°C fan/gas Remove the pithivier from the fridge and brush with the rest of the egg glaze. Using the tip of a small, sharp knife, score radial arcs into the pastry, working from the centre outwards and taking care not to cut all the way through. Seal the edges of the pastry carefully to stop the filling leaking out during baking.

Step 6

Bake for 15-20 minutes until puffed and golden. Turn the oven down to180°C/160°C fan/gas 4 and bake for 35-40 minutes more until a skewer pushed into the centre comes away clean and the pastry is deep golden. If it starts to brown too much, lay a sheet of foil loosely over the top.

Step 7

Remove the pithivier from the oven and increase the temperature to 220°C/200°C fan/gas Dust the pithivier with the icing sugar, then return to the oven for 3-4 minutes until caramelised and glossy.

Step 8

Transfer to a cooling rack to cool slightly (see Make Ahead). Serve warm with ice cream or cream