Preheat the oven (electric stove: 175 ° C / convection: 150 ° C). Grease a square springform pan (24 cm).
Break the chocolate into pieces for the batter. Melt with 250 g butter in pieces in a saucepan over low heat. Beat eggs, sugar and a pinch of salt with the whisk of the mixer for 3 - 4 minutes until creamy. Remove the chocolate butter from the heat and stir immediately into the egg mixture. Mix the flour, cocoa and baking powder. Mix quickly into the chocolate and egg mixture. Pour the dough into the mold and smooth it out.
Select and wash the blueberries for the topping (if necessary, let the frozen berries thaw). Beat the cream cheese, sour cream, sugar, eggs and starch until smooth. Fold the berries into the cream cheese mixture. Distribute carefully on the brownie dough. Bake in the hot oven for 40-45 minutes. Take out and let cool down. Remove from the mold and cut into pieces approx. 4 x 4 cm.
For 24 pieces, 200 kcal, E 3 g, F 14 g, KH 15 g per piece
Tip: If you use the dough as a basic recipe for brownies, then bake in the hot oven for about 25 minutes. The brownie shouldn`t be fully baked. This is why there are still traces of dough on the wooden skewer when testing the stick. Take out, let cool down. Carefully remove from the mold and cut into pieces approx. 4 x 4 cm.