Grease 12 muffin cups or line with paper muffin liners.
In a large mixing bowl, mix together flour, sugars, baking powder, baking soda, salt, cinnamon, nutmeg, and allspice. Make a well in the center.
In a separate bowl, whisk together buttermilk, marmalade, melted (cooled) butter, and egg. Pour into well in the center of the dry ingredients. Mix with a fork until dry ingredients are moistened. Stir in chopped cranberries (I chop mine in the food processor)and walnuts.
Use an ice cream scoop and spoon batter into muffin cups, filling 2/3 full. Bake in a pre heated oven at 400 degrees F. until tops are firm and lightly browned, about 20 minutes.
Cool muffins in pan on a rack for 5 minutes; turn out of pan to completely cool.