Place 125g of the blueberries in a pan with water and sugar and cook over a medium heat until they begin to release juice and the liquid in the pan starts to thicken. Set aside and allow to cool slightly for about 10 minutes.
To make the sponge, place all the ingredients into a large bowl and beat well until light and fluffy.
Turn the mixture into a greased and base-lined 6-8inch cake tin (square or round) and bake in a preheated oven for 20-25minutes until risen and golden.
When baked, remove from the tin and allow to cool. Once cooled, cut into 2cm slices.
To assemble the ‘trifle’ spoon the lemon curd into the bottom of a glass serving dish and cover with slices of sponge.
Spoon the blueberries and their juice over the sponge and allow the juice to soak down into the sponge for 2 minutes.
Cover with custard and place in the fridge for at least an hour.
To serve, top with whipped cream and decorate with the remaining blueberries and toasted almonds.