Add the measured cream to a large whipping bowl. Using a hand mixer, whip it at high speed until the cream's fluffy with stiff peaks.
2 cups heavy whipping cream
Add 1/2 cup of cookie butter (reserve the remainder) and condensed milk to a separate mixing bowl, and whisk them together until smooth & evenly combined. Add the salt to the mixture, and stir to combine.
1 14 oz can sweetened condensed milk, 3/4 cup cookie butter, 1/4 tsp salt
Pour 1/3 of the condensed milk mixture into the whipped cream, folding in to combine. Repeat in two more batches, until all of the condensed milk base has been combined.
Add half of the cream mixture to a 9x5 inch metal loaf pan, spreading it out in an even layer. Add the remaining 1/4 cup of cookie butter to the mixture in small dollops, then sprinkle half of the cookie crumbs evenly out overtop.
1 cup crushed biscoff cookies
Pour the remaining ice cream mixture over top, again spreading out in an even layer. Sprinkle the remaining cookie crumbs evenly out over top of the ice cream.
Tightly cover the loaf pan with plastic wrap, and freeze (flat) for at least four hours but up to overnight.
Remove the frozen ice cream from the freezer, and let it rest at room temperature for 5 minutes. Then scoop, serve, and enjoy!