Deceptively Delicious Cookbook - Peanut Butter and Banana Muffins

* Nonstick cooking spray

* 1 cup firmly packed light/dark brown sugar

* 1/2 cup natural peanut butter

* 1/2 cup cauliflower puree

* 1/2 cup banana puree

* 1 large egg white

* 1 cup whole-wheat flour

* 1 tsp baking powder

* 1 tsp baking soda

* 1/2 tsp salt