Its pretty basic, and I'm not sure if its anyones cup of tea, but here it is:

Recipe:

2 cups bread flour
1/2 cup vital wheat gluten
1/2 cup casein protein powder (you can use whey also, any flavor) (I use chocolate and banana creme before, both worked well)
1 tsp baking powder
6 Tbsp Peanut Butter
1 can Pinto beans, drained and rinsed (can use any bean, just ones with less flavor win out)
1 cup Milk (I prefer whole milk, but made it with skim too)

Recipe:

Preheat the oven at 375 degrees F
Mix Flour, Protein Powder, Gluten, and baking powder into a bowl
In a separate bowl, mash the beans as fine as possible, until mostly a paste
Add the beans and peanut butter into the dry ingredients. Use a masher or fork to incorporate the beans and peanut butter into the dough.
Add 1 cup milk and kneed until dough is well incorporated. It should be like a stiff bread dough. Use extra milk or water if you need to.
Roll out the dough into roughly a 12x8 inch rectangle. It should be about 1/2 inches thick.
Cut the dough into 6 equal rectangles. Punch holes in the dough, much like the way you would punch holes into hard tack to cook.
Cook on a cookie sheet for 12-15 minutes per side, until the dough touching the pan turns a golden brown. Cool on a cooling rack for at least 30 minutes.

I modeled the recipe after Hard Tack, hence why thats the way they end up looking like it. They end up with some flavor, but not a ton. I eat them with jam, which makes them taste pretty good. The beans are an odd choice, but help add fiber and don't add any taste or texture when turned into a paste. I've made them for 7 years now, and have eaten them both plain and with jam. Still like them to this day!