01 - Whisk together cold milk and instant vanilla pudding mix in a large mixing bowl for 2 minutes. Let stand for 5 minutes to thicken.
02 - Stir sweetened condensed milk into the thickened pudding until thoroughly incorporated.
03 - In a separate bowl, whip 1 cup heavy cream to soft peaks. Fold whipped cream and vanilla extract into pudding mixture until smooth and uniform.
04 - Arrange one layer of Biscoff cookies in the bottom of a trifle dish or 9x13-inch baking dish.
05 - Top cookie layer with half of the banana slices, followed by half of the pudding mixture.
06 - Repeat layering with remaining cookies, bananas, and pudding mixture.
07 - Cover and refrigerate for at least 4 hours, or overnight, to allow flavors to meld and cookies to soften properly.
08 - Whip remaining 1 cup heavy cream with powdered sugar and 1/2 teaspoon vanilla extract until stiff peaks form. Spread or pipe over chilled pudding.
09 - Sprinkle crushed Biscoff cookies over the top and add extra banana slices if desired. Serve chilled.