When a friend brought me a can of pinhead oatmeal from her trip to Scotland, I used some of them when I didn't have enough old-fashioned rolled oats for a batch of my favorite oatmeal cookies. The ratio was about 2 parts OFRO to 1 part pinhead. I've never gone back. The pinhead oats are steel-cut and seem to be slightly smaller than McCann's but I could be wrong - I've never looked at them side-by-side. When the Scottish can was gone, I switched to Country Choice Steel-Cut Oats, sold by Trader Joe's. I like a crisp cookie, so I sometimes use just the steel-cut, in the same amount as rolled oats. They are crunchy and nutty in flavor and texture, and could stand in for ground nuts in plenty of other recipes. I like to fool myself into thinking that if it contains oats, it's good for you....regardless of how much butter and sugar is involved!