Preheat the oven to 350°F. Coat 12 mini (2¼" x 4") loaf pans with cooking spray.
TO MAKE THE CAKE:
In a food processor, combine the applesauce and beans. Process until smooth. In a medium bowl, whisk together the oat flour, cocoa, baking powder, and salt.
In the bowl of an electric mixer fitted with the whisk attachment, whisk together the agave and eggs until light and foamy. Reduce the mixer speed to medium-low and pour in the coffee. Mix until combined. Add the bean mixture and vanilla extract. Beat until combined. Add the oat-cocoa mixture all at once. Beat on low until just moist, then increase the speed and beat for 30 seconds, or until smooth.
Pour the batter into the mini loaf pans (the batter should reach two-thirds of the way up the loaf pan). Bake for 20 to 25 minutes, or until a cake springs back when poked.
TO MAKE THE FROSTING (IF USING):
In the bowl of an electric mixer fitted with the paddle attachment, combine the cream cheese, agave, peanut butter, and salt. Beat until smooth. If the mixture is too soupy, refrigerate for 1 hour, or until firm. When the loaves are cool, remove them from the pans and top them with the frosting, spreading with a small offset spatula or the back of a small teaspoon.