Beat cream cheese and marshmallow fluff until smooth. Melt 1 ounce of semi-sweet baking chocolate in a microwave safe bowl on 50% power in 30 second increments, stirring between each, until melted and smooth. Beat into cream cheese mixture, then add vanilla, salt, and powdered sugar. Mix until smooth. Stir in chopped baking chunks and marshmallows.
Line a small bowl with plastic wrap (cereal bowl size). Transfer cheese ball mixture to the bowl and pack to compress, then wrap in plastic. This will form the “ball” shape. Chill at least 1-2 hours before continuing.
Finely chop the remaining 3 ounces of baking chocolate. Spread on a cutting board. Remove the cheese ball from the refrigerator. Remove plastic and place on chocolate pieces. Roll to press the chocolate all over the cheeseball, using your hands to form a ball shape.
Serve immediately with graham crackers, or wrap well and chill for up to 24 hours. (Best served after it’s sat at room temp for about 30 minutes.)