I'm always fiddling around with my ride food, but some things I've found that work and freeze well for me are:
- Snickers bars
- Peanut butter cups
- Caramel clusters
- Home made energy balls made of oats, peanut butter, coconut, flax seed, honey, mini chocolate chips and a dash of water to help hold it together. Sometimes I dip them in chocolate to help hold them together, but it's not as necessary in the cold. I call these Allergy Bombs because... Well... Just look at the ingredients.
I like everything I eat on the bike to be bite sized, so I buy/make my stuff accordingly. It's even more important below freezing in my opinion since you can pop it in your mouth if it's too hard and let it thaw a little before chomping down on it.