Reduce cream with nutmeg and bay leaves and reserve.
Lay out 3 similarly sized potato slices lengthwise with 50 percent overlap. Brush with clarified butter.
On one end, lay out a thin layer of spinach with a layer of ricotta salata on top. Spoon 2 tablespoons cream over cheese, then top with spinach; stuffing should cover no more than 30 percent of potato.
Roll potato sheets as tightly as possible and lay on a silicone baking sheet, seamside down.
Repeat with remaining potato slices, stuffing and rolling until all potatoes are used.
Brush tops of potatoes with clarified butter and sprinkle with pepper. Bake in a 350°F oven until lightly caramelized on outside.