For the cream cake with blueberries, quickly knead a shortcrust pastry from the pastry ingredients. Refrigerate for 1/2 hour. For the filling, mix the sour cream (or crème fraîche) with the egg, sugar, vanilla sugar and lemon zest until creamy.
Whip the cream until stiff and fold into the sour cream. Line the buttered 20 cm pan with the shortcrust pastry (it will be very thin – raise the edge about 1 1/2 cm), sprinkle with the almond breadcrumbs and fill with the blueberries.
Pour the filling over it and bake for 3/4 h at 165° C. Leave the cream cake with blueberries to cool in the oven.