Preheat your oven to 350 and gather together your baking ingredients and materials.
Combine banana, egg, peanut butter, and any optional ingredients in a mixing bowl.
Add carob powder and stir to combine.
Incrementally add flour, mixing into a cohesive workable dough. The amount of flour required will vary depending on your individual ingredients and any optional add-ins or substitutions. Note that if you are not including the optional ingredients in these treats, you may need to use a little extra flour.
Rest dough (optional but recommended).
Roll, cut into desired shapes and place on a prepared baking pan.
Bake for approximately 10-15 minutes. Cooking time will vary with shape/size, so keep an eye on the oven.
Cool before serving and storage. To make extra crispy, leave in oven for awhile after turning oven off.