Preheat oven to 425 degrees F. Spread the mayonnaise on bread slices and set on a baking tray. Divide the ham among each slice. Top each with 2 slices of cheese. Bake for 8 to 10 minutes, or until the cheese is melted and the bread is lightly toasted. Garnish each with a tablespoonful of cranberry sauce and a parsley sprig.