Preheat oven to 350°F.
Combine crushed pretzels, melted butter, and sugar in a medium bowl.
2 cups crushed pretzels, 1 cup salted butter, 3 tablespoons granulated sugar
Transfer the pretzel/butter mixture to an ungreased 9x13-inch baking dish. Spread the mixture evenly over the bottom of the dish. Bake for 10 minutes (NOT any longer or the mixture could stick). Transfer to a wire rack and set aside to cool completely.
While the crust cooks, bring 1 cup of water to a boil in a saucepan, then immediately transfer to a large heatproof bowl. Sprinkle the Jell-O over the boiling water and stir until it dissolves. Add 1 cup crushed ice and stir until ice dissolves.
1 cup water, 6 ounces pineapple Jell-O, 1 cup crushed ice
Pour the pineapple into a strainer, and use the back of a large spoon or a rubber spatula to press the pineapple against the sides and bottom of the strainer to press out as much liquid as possible. Add the drained pineapple to the Jell-O mixture and stir well. Refrigerate for 15 minutes or until partially set.
40 ounces crushed pineapple in syrup
While the pineapple mixture sets, in a large bowl, cream together the whipped topping, cream cheese, and sugar. Beat until smooth. Spread over the cooled crust.
2 cups whipped topping, 8 ounces cream cheese, 1 cup granulated sugar
Carefully spoon the slightly thickened gelatin mixture over the cream cheese layer. Cover and chill 4-6 hours (or overnight) or until firm.
Cut into squares, and if desired, garnish with whipped topping, pineapple tidbits, and fresh mint leaves.
Canned pineapple tidbits, Fresh mint leaves