To mascerate the berries, combine berries and sugar in a bowl. Leave for at least 1 hour, until berries soften.
Preheat oven to 350 F. Spray a 9” cake pan with non stick spray.
To make the cake, beat eggs in an electric mixer until well combined.
Add sugar and beat on high speed for 10 minutes, until batter is a pale yellow and has increased 2-3 times in volume.
In a small bowl, combine flour, baking powder and cardamom.
Add flour mixture to mixer and beat for 2 minutes on high speed.
Transfer to prepared pan and bake for 35 minutes, until tester comes out clean.
To make the custard, heat the 2 cups milk but do not boil.
In a bowl, beat egg yolks and sugar until light and creamy. Add cornstarch and whisk until thoroughly combined.
Slowly add heated milk while beating continuously to slowly temper the eggs. (if you add the hot milk to the eggs all at one time, you will get scrambled eggs)
Add vanilla and return to the stove.
Simmer for about 10 minutes while stirring constantly, until custard is thickened. Chill.
To make whipped cream, beat cream and sugar with an electric mixer until whipped cream consistency.
To assemble cake, split cake in half horizontally. Pierce both halves of the cake with a toothpick. Pour 2 tablespoons of the remaining milk over each half of the cake. (the cake is quite dry so you need to feed the cake with the milk to soften the texture)
On the bottom base, add a thick layer of custard, then a layer of the mascerated berries of jam (if using) and then some of the whipped cream. Add the top layer of the cake on top and cover the entire cake with the remaining whipped cram.
To make a feathered rustic decoration, use a silicone pastry brush to create the effect.
Decorate with fresh berries.
To serve, serve with the extra custard!