Beat the egg whites with a pinch of salt until they froth hard. Mix the yolks with the sugar and margarine well until the sugar melts, then add the flour mixed with the baking powder and mix. At the end add the beaten egg whites, taking care to mix from the bottom up. with slow movements until we incorporate all the egg whites. We cover a tray (34/22 cm) with baking paper, we pour the composition in the tray, we level it and then we place the blackberries passed through flour mixed with sugar. We put the tray in the preheated oven, it is ready when it passes toothpick test. Remove the tray from the oven and let it cool.
Cream: We prepare it in advance so that it is cold when we assemble the cake. In a saucepan we put the egg yolk, the sugar, the starch and we dilute it with the milk, we put it on the fire and we stir continuously until it starts to thicken. sachet with vanilla finesse, mix well and let it cool well. When it has cooled well, mix for a few minutes and then incorporate the whipped cream.
Bezel: Mix the egg whites with the salt powder very well, then add the sugar, little by little and continue to mix, dripping a drop of lemon juice. Mix until you get a firm meringue and the sugar is melted. I baked the cake, spread the meringue and put it in the oven on a very low heat, leaving the oven ajar. Leave it to dry well.
Remove the baking paper from the cake and turn the cake upside down, the bottom to become the top, because the blackberries are left at the bottom. Spread the cream and then place the meringue, easy not to break it too badly, it's quite I let it not erupt but I tried. I left it for about an hour and then I portioned it, I left it overnight, then with a serrated knife I portioned it trying not to break the meringue too badly.