Beat an egg in a bowl and add brown and vanilla sugar. Mix well, then add butter, which can also be replaced with oil.
Mix the baking powder with the flour and then slowly add them to the mixture.
Mash the bananas with a fork and add them to the mixture. Mix everything well to get a uniform mixture.
Pour the mixture into a 16 cm diameter cake pan and bake for 25-30 minutes at 200° C.
When the cake has cooled, use a knife to cut it into two halves, top and bottom.
Squeeze the juice out of the oranges and soak the bottom layer of the cake with it.
Pour milk into a container, add whipped cream powder and mix with a mixer to create whipped cream, which is used to spread the bottom layer of the cake.
Sprinkle the blueberries over the cream and then place the upper part of the cake on them, moistening it with the remaining orange juice.
Pour the sweet cream into the container and mix it in a couple of minutes into the whipped sweet cream, which is used to spread the cake. If desired, decorate the cake with crumbs and fruit.