I'm looking at the ingredient proportions of and trying to figure out how it would work, even with the corn syrup. It looks like there is too much butter to form a bond with the other ingredients but anyway...

Corn syrup adds thickness and flexibility so you need to replace it with something that does the same thing. Off the top of my head, I would increase the cream to 1/4 cup and reduce the butter to 1/4 cup. Put the cream and sweetener into a blender and pulse. Sprinkle 1/2 tsp. xanthan gum evenly over the top and and blend until thickened. Brown the butter in a frying pan - this will give the topping a nice caramel-y taste and so will adding caramel extract - and with the blender running, pour it into the cream mixture. Place the remaining ingredients in a bowl and stir in the cream mixture. Pour over the cooled cheesecake and chill until the topping is firm.

This is just a guesstimate so you may have to fool around with the proportions of butter and xanthan gum. The butter is what will help the topping to solidify.

Karen