Preheat the oven to 350 degrees F. Grease two 6-inch cake pans with nonstick spray and line with rounds of parchment paper. Grease again with nonstick spray.
Add the bananas to a blender. Blend into a puree. Measure out 1 1/2 cups.
Add to a bowl with the remaining ingredients. Stir together gently.
Divide in half and pour into prepared cake pans. (You’ll use about 1 1/2 cup batter in each.)
Bake for 22-24 minutes or until a cake tester inserted into the center of a cake comes out cleanly.
Remove from oven and place on a wire rack. Let cool completely in the pan.
Make the Blueberry Cream Cheese Frosting. Add the freeze-dried blueberries to a blender or clean spice grinder. Grind into a powder. Measure out 1/4 cup of the powder and add to a medium bowl. Add the cream cheese, butter, and vanilla extract. Beat until very smooth with a handheld electric mixer.
When ready to frost, place one cake, parchment paper removed, on a cardboard cake round or plate. Top with 1/3 cup of the frosting. Remove the parchment paper from the second cake and place on top of the frosting. Add the rest of the frosting on top and spread over the top and around the sides.
Sprinkle on additional freeze-dried or fresh blueberries if desired.
Dairy-free: Use melted coconut oil instead of the butter in the cake. For the frosting, use plain or vanilla nondairy Greek yogurt instead of cream cheese and omit the butter. (If using vanilla nondairy yogurt, omit the vanilla extract.)