Preheat oven to 400 degrees
Combine the pretzels, melted butter and the sugar and pour onto a foil-lined baking sheet. Bake about 7-10 minutes, or until bubbly and sugar mixture has started to turn a caramel color.
Remove from oven and cool completely.
Cream the cream cheese, then add drained pineapple and cream together. Fold in the Cool Whip and refrigerate.
About 30 minutes before serving; crumble the cooled pretzel pieces into the cream cheese mixture and stir in.