I guess it should be OK to sprinkle it lightly on top.
I cooked mine, mixed with old oat meal into a gruel and added several spoon full at a time. The worms went nuts,but so did the mites.

Flour become paste in the bin and molds badly. I wouldn't use it. But if you are determined to, use very small amounts.

I sprinkle couple tsp in with food during winter months. Worms like it.

Otis, I put some leftover cooked oatmeal in my bin once, before I started using the green bin recycling program.

Mites were all over it! I tend to have a mite problem in my bin. I hate these buggers.

As an aside, I once put a some brown rice in my bin that we didn't like. It overheated and killed my poor lads. I've never put rice in there since, and am careful with any new food.

I nearly killed my worms by feeding them rice. Anything that is very starchy (grains) should be fed to the worms in very small amounts. Mixing it with other foods helps. When I fed the rice in small amounts, the worms were fine. When I got impatient and feed a lot at once, things got really ugly.

Ive been in the habit of sprinkling corn meal in my bin and never had any problems with critters. But I tried some pancakes after seeing someone else do it on you tube but I wont do it again got a lot white worms from it.