I like to make bicuits from scratch. I have made scones since I was a kid, and use them for making Strawberry Short Cake, or just dipping in jam or mollasses. They would work on the trail I think. Simple recipe. I've varied it a bit but its basically tea biscuits.

Flour
Skim Milk Powder
Vegetable Oil
pinch of salt
baking powder
water
sugar or honey, or currants, not totally neccessary

In winter you could substitute butter or bacon fat for oil. You could in theory make your own baking powder from wood ash. The only thing totally neccessary to bring is the flour, milk, and oil, and I am not totally sure about the milk. The hard part is not the recipe but the baking method. A hot flat rock might work.

making bannock on you tube...

http://www.youtube.com/watch?v=p9nfJoJaM0k