For the short pastry, knead 250 g flour, 75 g sugar, 125 g butter in pieces, 1 egg and possibly 1-2 tbsp. cold water to a smooth dough. Grease a baking tray or a tart tin (28 cm Ø). Roll out approx. 2⁄3 of the dough to the size of the base and place it in the mould. Roll the rest of the dough into a long strand and press it down as a rim of approx. 3 cm. Prick the base several times with a fork and chill for about 30 minutes.
Mix 300 g of frozen berries and 2 tablespoons of flour and place in the refrigerator. Mix 150 g frozen berries and jam and put aside. Pre-bake the short pastry base in a preheated oven (electric cooker: 200 °C/circulating air: 175 °C/gas: see manufacturer) for 12-15 minutes.
For the sponge mixture, whisk 250 g butter and 250 g sugar with the whisks of the mixer until creamy. Stir in 4 eggs individually. Mix 350 g flour and baking powder. Alternately stir in crème fraîche, lemon peel and lemon juice. Briefly fold in the floured blueberries. Spread the sponge mixture on the shortcrust pastry base and smooth it down.
Bake the cake at the same temperature for 45-50 minutes. Remove and allow to cool. Roast the flaked almonds in a pan without fat.
For the frosting mix 100 g butter and icing sugar until creamy. Stir in the cream cheese bit by bit. Remove the cake from the tin. Spread with the Frosting. Decorate with jam mixture and flaked almonds.