1. Line cookie sheet or tray with waxed paper.
2. Place white chips and shortening in large microwave-safe bowl. Microwave at MEDIUM (50%) 1 minute; stir. If necessary, microwave at MEDIUM an additional 15 seconds at a time, stirring after each heating, until chips are melted and mixture is smooth when stirred.
2. Stir in pretzels, peanuts and cranberries.
3. Just as mixture is starting to cool quickly fold in mini peanut butter cups. Pour mixture onto prepared cookie sheet; spread to flatten mixture slightly. Cool completely. Break into pieces. Store in cool, dry place. About 7 cups party mix.