01 - In a large mixing bowl, whip the heavy cream using an electric mixer on medium-high speed until stiff peaks form, approximately 2 to 3 minutes.
02 - Gently fold the sweetened condensed milk, vanilla extract, and melted Biscoff spread into the whipped cream until fully incorporated and smooth, being careful not to deflate the mixture.
03 - Pour the ice cream mixture into a parchment-lined loaf pan, smooth the top with a spatula, and freeze for at least 4 hours or until completely firm.
04 - Remove the ice cream from the freezer and let it soften at room temperature for about 5 minutes to make scooping easier.
05 - Place 8 Biscoff cookies flat side up on a baking sheet. Scoop approximately 1/4 cup of ice cream onto each cookie, then top with a second cookie and gently press down to form an even sandwich.
06 - If desired, roll the exposed edges of each sandwich in crushed Biscoff cookies. Return all sandwiches to the freezer for 10 to 15 minutes to firm up before serving.