Thanks for the info. It's possible that I'm misunderstanding, but I'm still not finding the information I'm looking for. I can find an item count and gross sales (as well as the options to add to the report), but what I'm hoping to find is the number of transactions which included items from a given category. Is that possible? Is there something I'm missing?

Thanks again.

You're welcome - sorry for the misunderstanding, which was on my part.  I've played around with several reports, and I can't find any that will do what you want it to.  However, there is a way to get your desired information, but it will take a fair amount of spreadsheet work.  Go to Transactions, and set the date range to the desired value(s).  Then Export the data, using the Items Detail CSV option.  This report categorizes all of the sales in that date range, and includes the category for each item that was sold.  Now you can sort the sheet based on the category, which will group all items in the same category together.  Then you can calculate the total # of items in each category which were sold, and add up the gross sales and anything else you need for that category.

I hope this helps more than my first answer and gets you what you need.

Edit: you can also export the Transaction report using the Items Summary CSV option and you'll still get the category for each item without a lot of data that you probably don't need from the Items Detail report.  However, the Summary report doesn't give information for each transaction so if you need to link each item's sale to a specific transaction, you won't be able to get that.