I always start here so the compote has plenty of time to cool. Combine the berries, sugar, lemon juice, and zest in a saucepan and simmer until the berries break down. Stir in the cornstarch slurry, cook for one to two more minutes, then transfer it to a bowl to cool completely in the fridge.
While the compote cools, mix the crushed Biscoff cookies with melted butter until it looks like wet sand. Press it firmly and evenly into the bottom and up the sides of your springform pan. Pop the pan into the freezer for fifteen to twenty minutes so the crust firms up before filling.
Beat the room-temperature cream cheese until it's completely smooth, then mix in the powdered sugar, sour cream, vanilla, and salt. In a separate bowl, whip the cold heavy cream to stiff peaks, then gently fold it into the cream cheese mixture until light and fluffy.
Spread about two-thirds of the filling into the crust, pushing it up the sides to form a well. Spoon the cooled berry compote into the center, then top with the remaining filling, smoothing it flat to the rim. Chill for a minimum of six hours, or overnight for the cleanest results, then invert onto a plate right before serving.