Step 1

Lightly coat a 9"-diameter pie dish with nonstick vegetable oil spray. Stir 2 cups (250 g) finely ground Biscoff cookies (from about one 8.8-oz sleeve), 6 Tbsp. unsalted butter, melted, slightly cooled, and 1 tsp. Diamond Crystal or ½ tsp. Morton kosher salt in a medium bowl until crumbs are moistened and mixture holds together when squeezed in your hand. Transfer to prepared dish and press firmly and evenly across bottom and up sides of dish with a flat-bottomed measuring cup.

Step 2

Combine 2 tsp. unflavored powdered gelatin and 2 Tbsp. cold water in small microwave-proof bowl and let sit until gelatin swells, about 5 minutes. Microwave in 5-second intervals until melted (or set in a bowl of very hot water and let sit until melted).

Step 3

Pulse 8 oz. cream cheese, room temperature, ½ cup (1 stick) unsalted butter, room temperature, and one 14-oz. can sweetened condensed milk in a food processor until smooth, about 2 minutes. Add melted gelatin, zest of 1 large lemon, zest of 1 large lime, ¾ cup mixed fresh lemon and lime juice (from about 2 large lemons and 2 large limes), ¾ cup heavy cream, and 1 tsp. Diamond Crystal or ½ tsp. Morton kosher salt and process until well combined. Scrape filling into crust and smooth surface with an offset spatula.

Step 4

Stir ¼ cup orange marmalade in a small bowl to loosen, then spoon small dollops of preserves over filling. Using a chopstick or butter knife, swirl preserves into filling. Chill pie until filling is set, at least 4 hours and up to 1 day.