Combine the crushed pretzels, melted butter and granulated sugar in a bowl and stir until the mixture holds together when pressed. Press firmly into the bottom of a 9×13-inch baking dish. Bake in a preheated 350°F oven until set, about five minutes, then remove and let cool completely on a wire rack.

In a medium bowl beat the softened cream cheese with the sifted powdered sugar until smooth and fluffy. Fold in the whipped topping until no streaks remain and the mixture is uniform in color. Spread evenly over the cooled pretzel crust and return the pan to the refrigerator while you prepare the gelatin.

Dissolve the peach-flavored gelatin in the boiling water, stirring until fully dissolved. Stir in the cold water, then gently fold in the diced, well-drained peaches. Let the mixture cool briefly until it begins to thicken at the edges, then carefully pour it over the cream layer, tilting the dish as needed to create an even layer. Refrigerate until completely set, at least four hours or overnight.

Use a sharp knife wiped clean between cuts to slice into squares. Serve chilled for best texture and flavor contrast.