Place a steamer basket in a large pot filled with a few inches of water. Bring to a simmer. Add potatoes to the basket and cook until potatoes are soft, about 15 minutes.
Transfer potatoes, melted butter, 1 ½ teaspoons salt, and ½ teaspoon pepper to a food processor. Puree until smooth, scraping down bowl as needed; taste and add more salt or pepper.
Transfer to a large bowl. Serve buffet style with Challenge Dessert Snack Spreads and toppings.