What's missing???

I've nearly got a recipe worked out for a really simple, fast and hearty cold oatmeal dish (perfect for summer) I had a few years ago, and I thought I'd share it and see if you guys could help me fine-tune it - and enjoy it, of course!

1 c. oatmeal (uncooked)
1 c. water
1/2 c. plain yogurt
3 Tbsp. brown sugar
1/2 tsp vanilla
1 green apple, diced
dried cranberries (?)
chopped walnuts
???

Mix the oatmeal and water together, and let it sit for a few minutes, while you dig out everything else and dice the apple. Mix in the yogurt, vanilla and brown sugar (vanilla and brown sugar to taste - it should be very slightly sweet) Then add in the diced apple, a handful of what I think should be dried cranberries (Craisins were too sweet), maybe a handful of chopped walnuts, and ???. There's at least one spice missing - something with bite. I've tried cinnamon, and that definitely wasn't what was missing. Any other ideas for my next batch?

Anyway, this is a really good recipe - you've got the brown sugar and the sour apple and the tart cranberries and whatever spice is missing really giving it a nice balance of flavors. You've also got carbs, dairy, nuts and fruit all in one go. Enjoy!!!