Preheat oven to 400 degrees F.
Mix together both flours, baking powder, baking soda, cinnamon, and salt; set aside.
Beat together eggs, brown sugar, applesauce, and oil until smooth.
Pour wet mixture into the dry mixture; stir until just moistened.
Fold in rhubarb.
Prepare muffin tins with liners or spray well with nonstick spray.
Fill muffin tins two-thirds (2/3) full of batter.
Mix together the cinnamon and sugar for the topping. Sprinkle each muffin with the topping mix.
Bake for 18-20 minutes or until a toothpick comes out clean.