This baked brie en croute with caramelized red onion jam recipe looks stunning yet requires minimal effort. Often, a baked brie recipe is an assembling activity of store-bought ingredients, but this one has a homemade touch that elevates it and makes it feel special. A quick and easy red onion jam easily comes together by caramelizing red onions and perking them up with apple cider vinegar, light brown sugar, and honey. This jam is the star of this , as it balances the richness of the puff pastry and makes the brie ever so flavorful.