Tarte Tropézienne

Method

1. The first step to make the creme légère is to make a creme patissière. In a bowl, whisk together the sugar, whole egg and yolk, and cornflour. Put the milk in a saucepan and bring to a simmer. Remove the milk from the heat and gradually pour into your egg mixture, whisking constantly. Return this entire mixture back to the pan and cook over a medium heat. Keep whisking the crème pat as it cooks; it will thicken quickly.
2. Once it has come to the boil (it should have lava-like bubbles erupting), remove from the heat and transfer to a bowl. Leave to cool for about 10 minutes, then beat in the butter. Once the butter is well incorporated, cover the surface of the creme pat with a layer of baking paper. Allow to cool, then chill completely.
3. Lightly butter a 23cm springform cake tin on the base and sides. Turn out your brioche dough onto a lightly floured surface and fold the 4 corners of the dough into the centre. Flip the dough over and use a rolling pin to roll the dough gently to form a flat disc about 20cm in diameter. Put it inside the cake tin and press the dough out to the sides of the tin. Loosely cover and place somewhere warm to rise for about 1 hour. The dough is proved when you press the surface lightly with a finger and the indent stays without bouncing back.
4. Heat the oven to 190°C fan/gas 7. Brush the top of the dough with the beaten egg and milk mixture and sprinkle generously with demerara sugar to form a sugary crust. Bake for about 40 minutes. I find the easiest way to check the brioche is ready is to use a probe thermometer to take the core temperature; it should be above 92°C. You can also test with a thin skewer like you would a cake – push it into the centre and remove it and if it comes out clean, it is ready. Allow the brioche to cool in its tin for the first 20 minutes, then remove from the tin and cool completely on a rack.
5. Beat the crème patissière so it is completely smooth. Whip the double cream to stiff peaks, then gently fold it into the crème patissière to create creme légère. Be firm but gentle when folding in the cream. We want to keep this mix quite stiff so it holds its own shape but still keep the lightness of the cream.
6. Once the brioche is completely cooled, use a sharp knife to cut horizontally to create two even round sponges as if for a victoria sandwich cake. Brush each cut side generously with the elderflower cordial, then spread a good layer of raspberry jam on the base. Pipe or spread your creme légère on top of the jam, then top with the other brioche, pressing down gently to seal it all together. Refrigerate for 1 hour to let everything set, then enjoy.