I was given a bunch of what I consider "cheater" quilt fabric. It is already quilted and has some batting on one side and fabric on the other. I have no idea what to do with it. Suggestions?

Make tote bags, placemats, or pet bed liner.

All good possibilities!
Lots more things you could make. Keep in mind that by adding a backing/lining, this new fabric will not be quilted, and so, you could end up with shifting and shrinkage problems.

If you don't really care for the pre-quilted fabric, you could always "bury it", using it as a batting (even with the cheater fabric included)!!

Yours may be different, but something to check/consider before deciding how to use this fabric .... The pre-quilteds that I have seen have had a backing stitched right with it. They seem to have a different sort of stitching than we traditionally expect of machine quilting, which then is unstable, and come apart with little usage.

I used the prequilted fabric as a baby quilt backing. I just added quilting to it to quilt the sandwich.

Make a jacket out of it. They’re very popular right now.

If it's cotton, soup cozies are fun.

Casserole carriers