Preheat oven to 350 degrees. Place cupcake liners into muffin pan.
Chop cauliflower and place in a microwave safe dish. Cover and cook for 3-4 minutes, or until soft enough to puree but not to liquefy.
Place cooked cauliflower and banana into a food processor; blend well.
Mix half the brown sugar with the peanut butter and cauliflower puree. Whisk in the egg; set aside.
In a separate bowl, mix flour, baking powder, baking soda and salt; add to wet ingredients and stir until just combined. Fold in the remaining brown sugar. Pour into muffin cups; bake for 15-20 minutes; until a toothpick inserted comes out clean.
Allow to cool before serving.