Heat up your oven to 175 ° C.
Slowly melt the vegan butter in a saucepan and allow to cool slightly.
Now add vegan quark, plant-based milk or cream, raw cane sugar and cornstarch into a mixing bowl or blender and blend well with a hand mixer (or blender). Then stir in soft butter with lemon juice. Finally, carefully fold in 2/3 of the blueberries.
Now put the filling on the dough and smooth it out.
Crumble the remaining dough into crumbles and spread with the remaining blueberries on top of the filling.
Bake the cake on a medium rack in a preheated oven at 175 ° C for about 60 minutes.
Afterwards, let the cake cool and serve. (Optionally, you can also dust the cake with a bit of icing sugar before serving).