This pasta dish is a holiday staple in some Italian households.
Bring a large pot of salted water to a boil. Prepare an ice-water bath. Working in batches, cook pasta sheets for about 2 minutes. Immediately transfer to ice-water bath to cool. Remove from water, rub a drop of oil on each sheet, and stack on a plate.
Combine 1 teaspoon salt, the ricotta, garlic, herbs, red-pepper flakes, and pepper in a medium bowl.
Preheat oven to 350 degrees. Spread oil in a 9-by-13-inch baking dish. Line up pasta sheets lengthwise on a clean, dry work surface. Spread cup ricotta mixture on each sheet, about 1 inch from bottom. Roll up, overlapping ends to close. Arrange, seam sides down, in rows in baking dish.
Immediately pour Parmesan cream over cannelloni. Bake until tops are golden brown and slightly crusty, 50 to 60 minutes. Serve warm.