How can I incorporate powdered peanut butter into a boxed banana bread? My husband has made this boxed Gluten Free Banana Bread Mix a number of times. It's easy, always comes out moist, and stays fresh for 3 or 4 days.

Ingredients:
1 package Banana Bread Mix from Anna
2 jumbo eggs
⅓ cup oil
3 ripe medium bananas pureed in a food processor or blender 
(approximately 1 cup)
⅔ cup chopped nuts (optional) (He leaves these out.)

Directions:
 1.  Preheat oven to 350 degrees. Set rack to center.
 2.  Grease 8 ½ x 4 ½ inch. loaf pan.
 3. In a medium-sized mixing bowl, mix all wet ingredients 
until creamy.
 4. Add Banana Bread Mix from Anna™ and stir until well 
blended. Fold in chopped nuts.
 5. Spoon batter into prepared pan and bake for 1 hour, or until 
center tests clean with a toothpick or knife. Let cool in pan 1 hour before slicing.

To add some additional flavor, he'd like to incorporate powdered peanut butter.
The powder contains only organic peanuts, organic coconut sugar, and salt. (When making peanut butter, the ratio is one tablespoon water for each two tablespoons of powder. That ratio makes a thin consistency of peanut butter, similar to many brands bought off the shelf.) 

Obviously he can't predict the level of peanut flavor, as that would be a matter of trial and error, but he'd like to start by adding 2 tablespoons of powder into the pre-made mix. His concern is that the banana bread will be dry. To avoid that, is there a way to adjust the other ingredients? 

Here are some pictures of the peanut powder:

 


It's a light, loose consistency which looks like this:
He's right. It likely would come out with a different consistency. That 1/3 cup of oil and maybe some egg would be partly absorbed by the peanut butter. That will affect the texture.

For a first try: In a separate bowl I would reconstitute the 2 T of peanut butter with water (4 T in this case). For easier measuring 4 T = 1/4 cup.

Add the reconstituted peanut butter to the batter, two options to mix in:


thorougly mix in the peanut butter until it's fully incorporated into the batter
or, swirl it in, kind of like a chocolate marble cake