Mix cream cheese and 1/2 cup sugar together in a bowl; add pineapple and mix well. Fold whipped topping into pineapple mixture; refrigerate until chilled, about 30 minutes.

Preheat oven to 400 degrees F (200 degrees C). Line a baking sheet with a silicone mat or parchment paper.

Combine pretzels, butter, and 1/3 cup sugar in a bowl until evenly coated; spread onto the prepared baking sheet.

Bake in the preheated oven until pretzel mixture holds together like toffee, 6 to 8 minutes. Remove pan from oven and cool. Break pretzel mixture into pieces and mix into pineapple mixture.