My niece thinks bread flour and yeast are right for the crumpet recipe. Though baking was not her career path.

So what is the difference between a bun and a bap?

In the 60's, when it was easier to test these things, TV reporters could make a statistical analysis that it depended which side of the A5 the question was asked. And I have seen similar treaties on phrases such as differing salutations - and the A5 being the divide. Makes sense, the road was important for a long time and people were more likely to travel along rather than across it.
I bet there were enough differences across the Pennines - their roses were a different colour!