My horse Magic loves his treats. Since I can't do much else with him anymore, grooming, loving and treats are our interactions.
I find the sugar free peppermints at Wal-Mart. I haven't found a grocery store brand that has them here but all the WM's do. So try that.
This brand is Bob's Starlight Mints made by Farley's & Sathers Candy Co.
I will occasionally bring him a piece of broccoli stem. He enjoys getting something "green". (before I go any further I use treats in moderation - small amounts not handfuls)
He also likes a few herbs. I have chopped Hawthorn berries & leaves and I toss a small palmful of each in a bucket along with a few sunflower seeds as something different from time to time. Always keeping total amounts small, plus he seems to tolerate these ok. Possibly not all IR horses can, I don't know.
But I also want to recommend the Skodes Horse Treats. Magic was a taste tester for the Nutty Seed cookies and was one of the few that turned his nose up to them. I tossed them in the freezer and forgot about them for awhile. When I discovered them I gave him a "frozen" one and he has eaten them every since. Go figure!
And he LOVES the new Minty Rose brownies as well.
The mix that someone mentioned is the Nutty Seed recipe in dry form for you to bake up the cookies yourself. It gives you the option of thick and moist or thin and hard, depending on your horse's liking.
But now for a funny story.
Today I was standing in the aisle of the barn I board at with Magic held loosely by the lead rope busy talking. The refrigerator is also in that aisle. Magic starting using his lip to get into the freezer and actually opened the door. He knows where his cookies are!!
He is a very happy horse when he gets his peppermints and his Skodes treats.