School bread tastes like one of the BEST creamy/pudding/custard type filled doughnuts you've ever had. I've eaten it 5-6 times now. I don't remember any black 'flecks' of any sort in it. I know that a few of ours have tasted more of a 'vanilla flavor' than others have, so could those flecks be crushed/chopped vanilla bean? This, by far is a favorite of my family! Also, those black 'flecks' that you may have thought you saw could possibly be the camera's version of the tiny little air pockets inside of the doughnut/bread and not black flecks at all.
I know that a lot of people have different feelings about what 'yummy treats' are- some prefer certain tastes, textures, some prefer light/heavy...BUT, with the schoolbread, SO MANY people LOVE it and that's why it's on the 'must try' list at Disney!