Add sugar, baking powder and melted butter to the oat flakes.
Stir well, tamp a little and leave for 20 minutes to allow the flakes to absorb the oil.
In a separate bowl, put the cottage cheese, sugar, vanilla sugar and eggs. Beat the blender into a homogeneous mass.
My shape is 24 cm, I covered the bottom with parchment. Spread half of the dough and tightly tamp it. Spread the curd filling on top.
Cut the plums in half and remove the stone. Spread on the curd filling, pressing a little into it.
Sprinkle the remaining "dough" on top, it is most convenient to do this with your hand, so it is evenly distributed. Bake in a preheated 180 degree oven for 30-35 minutes.
Let the finished cake cool completely and put it in the refrigerator for a few hours. So the curd filling will grip well and the top layer will not crumble when sliced. It turns out to be crispy on top, and soft inside, with a slight sourness of plums. You never think that with ordinary oatmeal it will be so delicious!