Since baking with Splenda is not unique to Kosher food you might want to repost this on the General Topics board. An awful lot of Chowhounds with experience in the kitchen hang out on the General Topics board and some of them would probably be able to contribute to the discussion.
I made a successful pareve cheesecake, use it in cakes, muffins, etc.
One ready-made pareve pie crust (or make your own with Pareve graham crackers and margarine)
1 package of tofu
1 package of tofu cream cheese (tofutti)
1 cup sugar (or splenda)
1 tsp vanilla extract.
Blend ingredients in a mixer, food processor or blender. Pour into crust. Bake for 1 hour at 325. Cool, then place in fridge for several hours prior to serving. Option- add 1 can of pumpkin (libbys) to make a pumpkin cheesecake (you'll have leftover liquid, pour into custard cups, bake, top with pareve whipped cream)