FG too low! Help!
 

so I've had this problem with the last few beers I've made, I know it's my own fault for over yeasting, but I'm trying to solution to the problem/mistake. Does anyone know of a good, unfermentable sugar/sweetener that can add some sweetness to the finished beer, or a good way to keep the yeast from restarting when adding more sugars to the beer?

Not sure why you think you "over yeasted", but lactose/milk sugar will give you the sweetness you're looking for. You can add it at bottling time.

Also maltodextrine. It is mostly unfermentable and will increase body and sweetness.

it won't be the same as hitting your FG and you will just be settling for second best.

How much yeast are you using? And what sorts of temperatures have you been using for fermentation?

I have a question. Are you getting below your target FG? Or are you hitting your target which is lower than your taste (some people like maltier beers)?

If you are getting below your target, something is wrong (either your target, your mash temps, your top off water, you have an infection, etc.). If you just don't like how your beers turn out (but they are "correct"), try a different beer instead of tweaking recipes.