I use the banana one in my peanut butter cookie recipe. I hated standard peanut butter cookies because they had too much flour, not enough peanut butter, and I could always taste the leavening agent.
I started tweaking things and accidentally ended up with a vegan, gluten free recipe that can only not be eaten by people with peanut allergies or carb dodgers. And since you don’t need to split an egg to make a smaller batch you can make smaller batches more easily.

Piller’s Peanut Butter Cookies.
Servings: 15 three inch cookies.
1 teaspoon baking soda (not powder).
1/4 tsp baking powder
1/2 cup demerara sugar
1/2 cup powdered demerara sugar (half a cup demerara in a spice grinder and remeasured to half a cup).
1/2 a banana
1 cup all-natural chunky or smooth peanut butter.

• preheat oven at 350f.
• in a small bowl smash the banana with a fork until creamy with no chunks.
• In a large bowl mix the the baking soda, baking powder and sugars.
• add the peanut butter and banana and mix thoroughly.
• Spoon one to three tablespoon amounts onto silicon baking mat in a baking sheet or an insulated baking sheet.
• flatten them to about 1/3 inch (1 cm) thick with a fork or meat tenderizing hammer.
• bake for 10-15 minutes, they will be very soft.
• let cool completely and they will firm up into crispy goodness.