Mazurek (Polish sheet cake)

Method

1. To make the pastry, whizz together the flour, almonds, butter and a pinch of salt in a food processor until the mixture resembles fine breadcrumbs. Add the sugar and egg yolk, then whizz again until the pastry comes together into a ball (if you don’t have a food processor, rub together the flour, almonds, sugar and butter with your fingers in a bowl, then stir in the egg yolk with a wooden spoon). Shape the dough into a rough rectangular shape, wrap in cling film and chill for 40 minutes.
2. Meanwhile, for the almond filling, wipe out the food processor bowl and tip in the ground almonds, icing sugar and pinch of fine sea salt; pulse until evenly mixed. Pour in the egg white and almond extract and whizz again until the mixture resembles a smooth paste (or mix together well with a wooden spoon), then set aside.
3. Dust the work surface with flour and roll the pastry out into a rectangle about 5cm or more larger than the baking tin. Use the rolling pin to roll the pastry up and lift it gently into the lined tin. Gently push the pastry into the edges of the tin and up the sides, making sure the baking paper is visible around the edges. Trim the excess pastry. Chill for 20 minutes in the fridge (or for 10 minutes in the freezer). Heat the oven to 180°C fan/gas 6.
4. Line the pastry case with baking paper and fill with baking beans or uncooked rice. Bake in the oven for 10 minutes, then remove the baking paper and beans/rice and return to the oven to cook for a further 10 minutes. Remove from the oven and leave to cool slightly.
5. Spoon the jam over the pastry base. Roll out the almond paste between 2 sheets of baking paper dusted with icing sugar. Lay the almond paste on top of the jam and press in well. Return to the oven for 5-8minutes to toast the almond layer, then remove and leave in the tin to cool completely.
6. While the tart cools, make the chocolate topping; put the cream, vanilla and sugar in a pan over a medium heat and bring slowly to the boil. Put the chocolate and butter in a large bowl and pour over the hot cream mixture. Leave for a minute or so, then whisk slowly until the chocolate is melted and the mixture is smooth. Pour the chocolate into the tart case and leave to cool, then chill for 2 hours until set. Carefully lift the tart out of the tin using the baking paper and transfer to a serving board. Decorate with glacé cherries and flaked almonds and serve.