The problem I have seen with baking in the woods is two fold.
One: carrying ingredients that I don't want to carry, like butter and oil and stuff. I like dry powder+water=food, myself.
Two: carrying equipment to cook it with, since I only backpack, carrying camp ovens or Dutch ovens isnt going to cut it.
The solution for a lot of baked goods seems to be:
Cook the damn thing at home and reheat it.
I have a snow peak 700ml mug, and a gigapower canister stove. After much trial and error i figured out how to brown a roll in the woods without burning it. A restaurant mining expidition recently turned up little packs of "butter" that keep without refrigeration, so using the mug and stove I can have warm buttered brown-and-serve rolls in the back woods. The technique could be applied to precooked pills bury cinnamon rolls, and maybe brownies. Brownies crumble... You may have issues with this.
The method is as follows:
Take two pieces of steel wire. I used aircraft safety wire, it's about 20guage. Bend the wire into a support platform, with hooks at the top and a 90 degree horizontal bend at the bottom. Placed in your cup, the hooks at the top should be spread out like a compass... Equal points at N E S and W. looking into the cup, you should see an X about an inch off the bottom. Sit roll on X, put lid on cup. Put cup on stove and turn on lowest flame possible. You may even want to turn the flame off and back on a few times.
Check roll every few minutes. If the roll falls off the x onto the cup bottom, it will burn. Likewise any crumbs that fall to the bottom. Brownies may be better suited sitting in a silicone baking cup or little aluminum cup (the bottom half inch of a soda can?), especially the gooey ones.
My next test will involve cinnamon rolls, maybe adding a few drops of water in the bottom to moisten the surface of the roll.