Put the potatoes in a medium pot and cover with cold water by 1 inch. Bring to a simmer over medium-high heat, then cook until tender, about 10 minutes. Drain the potatoes very well until dry.
Pass the potatoes through a potato ricer into a large bowl. Add the butter, sugar, cream and salt and mix well to combine. Add the flour and knead well to incorporate.
Preheat a 10-inch cast-iron skillet over medium-high heat.
Generously dust a work surface with flour. Scoop a level 1/3 cup of dough. Dust your hands with flour and roll the dough into a ball, then flatten it into a disc and place it on the work surface. Dust the top with flour and roll it out to a thin, 8-inch round, moving the round often to ensure it doesn't stick.
Carefully lift the round with your hands or the rolling pin and lay it in the preheated skillet. Cook until the underside is golden brown in spots, about 1 minute. Flip the lefse and cook until spotted on the underside, about 1 minute more. Transfer to a clean dish towel or paper towel. Repeat with the remaining dough, stacking the lefse between towels.
Serve with the Lingonberry Cream Cheese.
Lingonberry Cream Cheese:
Beat the cream cheese, sour cream and sugar in a medium bowl with an electric mixer until smooth. Pour into a serving bowl and swirl in the lingonberry preserves until just barely mixed and still streaky. Top with the lemon zest.