Grate the remaining 200g beetroot, mix in a bowl with 1 tablespoon of orange juice, balsamic vinegar and a little salt. Puree the soft beetroot cubes, add the cream and season with salt and cayenne pepper. Do not cook anymore, just keep it hot, otherwise the cream can curdle. Stir the raw beetroot rasp into the puree, fold the cooked pasta into the sauce and let it steep for a moment. Arrange on plates and sprinkle with plenty of parmesan cheese.