Cover potatoes with water and cook until tender. Run hot potatoes through a potato ricer. Place into a large bowl. Beat butter, cream, salt, and sugar into the hot riced potatoes. Let cool to room temperature.
Stir flour into the potato mixture. Pull off pieces of the dough and form into walnut size balls. Lightly flour a pastry cloth and roll out lefse balls to 1/8 inch thickness.
Cook on a hot (400 degree F/200 C) griddle until bubbles form and each side has browned. Place on a damp towel to cool slightly and then cover with damp towel until ready to serve.