Carole, a reader, emailed to ask where I bought the cinnamon extract I used in my Sin-a-Bun cookies. I found it in the extract section of the baking aisle in my grocery store. (But, as regular readers know, my grocery store has got little-to-no organizing principle. So when I say "in the baking aisle," that translates to "that tiny section between the eggs and the salsa." Don't ask...I'm still trying to figure it out.) So if I can find cinnamon extract in my grocery store, you should be able to find it in yours.
I use McCormick brand cinnamon extract. Nothing fancy--just good old omni-available McCormick. Here's a link to the cinnamon extract page on the McCormick website. Perhaps knowing what the packaging looks like will help you find it more easily on the supermarket shelf.
Less common than cinnamon extract, but just as easy to obtain, are cinnamon chips. I buy these through the King Arthur Baker's Catalogue online store. I buy these guys two bags at a time and keep them in the refrigerator, where they keep for months on end. They taste great--just like the crumb topping on a coffee cake--and can be used in a bunch of recipes. I melted two tablespoons' worth and used it in the cinnamon slurry I used to fill the Sin-a-Bun cookies' thumbprints.
I hope this helps, Carole. Let me know how they come out!