1 . Stage
Preheat oven to 400 degrees F (200 degrees C). Pierce potatoes with a fork and bake until soft, about 1 hour. Remove from oven and cool until potatoes can be handled, about 20 minutes.
2 . Stage
Reduce oven temperature to 350 degrees F (175 degrees C). Grease a large baking sheet.
3 . Stage
Meanwhile, place olive oil in small skillet over medium heat. Add shallots and cook and stir until softened and beginning to brown, about 10 minutes. Set aside.
4 . Stage
Cut potatoes in half lengthwise and scoop out pulp, leaving a thin shell. Set shells aside. Place pulp into a blender or food processor and blend until smooth. Add ricotta, salt, pepper, ginger, and sugar to the blender; blend until smooth.
5 . Stage
Return potato mixture to a bowl; stir in shallots, Parmesan cheese, and sage. Spoon mixture back into potato skins. Place potatoes on prepared baking sheet.
6 . Stage
Bake until heated through, about 30 minutes.