Prepare and bake your tart dough. If you are going to make our Tart dough recipe, you can click on the "Tart dough" ingredient on the left and follow the instructions.
Blend the walnuts to a fine powder. Add sugar, pinch of salt, 1/2 vanilla bean seeds, softened butter and flour. Mix well. Transfer to a large bowl, add two eggs and honey and combine well. Place in a fridge for 15 minutes.
Preheat the oven to 180°C / 355 °F. Pit the plums and slice them thinly. Spoon the walnut filling into the prebaked tart shell, spreading it evenly over the bottom. Arrange plum slices over the walnut filling and place the tart in the oven. Bake for 50 minutes at 180°C / 355 °F or until golden brown. Serve with vanilla ice cream or a dollop of sour cream. Enjoy.