1. Preheat oven to 425°F. Coat two large baking sheets with nonstick cooking spray.
2. In a medium saucepan over medium heat, combine butter, milk and sour cream, and cook for 2 to 3 minutes, or until a full boil is reached. Add the flour all at once and stir vigorously with a wooden spoon, until dough mixture pulls away from the sides of saucepan and forms a ball. Continue to cook for another minute or until excess moisture is gone, stirring constantly. Transfer to a large bowl and cool for 5 minutes.
3. Beat in eggs one at a time by hand or with an electric mixer on low speed, making sure each egg is fully incorporated into the dough before adding the next egg. Beat the dough until it is shiny and smooth. Stir in cheese, Potatoes and salt, and mix well. Drop a tablespoon of dough at a time onto baking sheets, about 1-½ inch apart.
4. Bake uncovered for 28 to 32 minutes, or until golden brown and firm to the touch. Serve warm or at room temperature.