In a food processor, blend the cheese crackers to very fine crumbs.
In a large bowl, mix the Cheddar, cream cheese and macaroni and cheese powder until fully combined. Roll into a ball and coat with the cheese crackers crumbs. Wrap fully in plastic wrap and form into a pumpkin shape. Using a wooden spoon or skewers, make the ridges of a pumpkin.
Unwrap the cheeseball pumpkin. Place the pepper stem and parsley sprig on the top and sit on top of a plate of green tortilla chips.