Line an 8-inch square baking pan with 2 sheets of parchment paper, positioning them perpendicular to each other so that the parchment hangs about 2 inches over all 4 sides of the pan to form a sling.

Process 50 vanilla wafers, 2 tablespoons granulated sugar, and ½ teaspoon kosher salt in a food processor until the cookies are the texture of sand, about 15 seconds. Remove 1 tablespoon of the vanilla wafer crumbs and reserve for garnish.

Add 1 stick melted and cooled unsalted butter to the food processor and pulse to combine, 6 to 8 (1-second) pulses.

Transfer the mixture into the baking pan. Use the bottom of a flat measuring cup or your fingers to press the crumbs into an even layer, making sure to reach the edges and fill the corners.

Wipe the food processor clean. Add 12 ounces quartered and pitted peaches, and process until smooth. Add 1 (14-ounce) can sweetened condensed milk and ¼ teaspoon kosher salt, and process until combined. Transfer to a large bowl. Wash and dry the food processor and blade.

Add 2 cups cold heavy cream to the food processor and process until soft peaks form, 1 to 2 minutes. Reserve and refrigerate a heaping ½ cup for garnish. Gently whisk the remaining whipped cream into the peach mixture until no streaks remain.

Transfer onto the crust and smooth into an even layer. Cover and freeze until firm, at least 5 hours or up to overnight.

Grasping the excess parchment, lift the slab out of the pan and place on a cutting board. Cut into 12 bars, wiping the knife clean between each cut for the cleanest-looking slices. Top each piece with a dollop of the reserved whipped cream, a sprinkle of the reserved vanilla wafer crumbs, and a peach slice.