What I actually TAKE backpacking for high calorie stuff:
1) Hudson's Bay Bread - google the recepie. A 3 inch square of this slathered in peanut butter has as much voom in it as an entire commercial dehydrated backpacking meal.
2) Walker's shortbread cookies - oh god these are good, and so bad for you. I only take them winter hiking.
3) smoked almonds. almonds have tons of calories, and tons of fibre - all good.
4) sausage - I love landjaeger or dry salami or pepperoni sticks
6) Cheese - parmigiano reggio keeps forever, softer stuff less so.
7) Chocolate
So my snack loadout for 4 days out, doing 90 km in four days last weekend was:
6 landjaeger sausages
1 175 gram piece of emmentaller cheese
1 can black diamond smoked almonds (in a ziploc)
4 3 inch squares of hudson's bay bread
150 grams of peanut butter.
A small ziploc sandwitch bag full of dried fruit (mangos cherries, cranberries)
I ate oatmeal or egg and taters with coffee for breakfast,
and a dehydrated backpacking dinner for dinner.
I walked off the trail with a sausage and small piece of cheese which I ate in the car at the trailhead, and a few almonds and fruit, half an HBC bread, and some peanut butter.
In other words, I a had enough snacks to do an extra day if I needed to. - about as I had planned it. I didnt' feel hungry or wanting and made good time.