I'm celiac and low carbing and I use ground nuts like almonds in recipes instead of breadcrumbs or matzo meal - they do the same job of soaking up moisture in stuffings.

I don't know whether any heat stable sweetners are kosher (I've just looked at my jar of splenda and it doesn't say) but there are some great kosher and passover kosher cake recipes in Claudia Roden's cookbooks which use nuts instead of grain products - I've adapted those very successfully by substituting splenda for the sugar.

let me know if you'd like me to post some actual recipes - they do come out really well, but are better after a couple of days as the nuts soften with storage. Also the recipes with a bit of fat like melted butter or oil work better as splenda cakes can be quite dry compared to sugar ones.