Worried he might wake everyone at the castle with his deep, booming barks, they hastily fed him treacle fudge from a tin on the mantelpiece, which glued his teeth together.
If they're using other words like caramel or treacle or nuts or chocolate, those are non-fruit words and they are suggesting low acidity in that regard.
On their last evening, Mrs. Weasley conjured up a sumptuous dinner which included all of Harry's favorite things, ending with a mouthwatering treacle pudding.