Start by mashing the banana well. In a medium bowl sieve the dry ingredients together, flour, salt,cinnamon and the baking powder. Keep aside. Next use an electric stand mixer or hand mixer to cream together the oil and sugar.
Add an egg, vanilla essence and beat till light and fluffy. Now, add the mashed banana, peanut butter,desiccated coconut and yogurt and mix till smooth.
Now add the dry ingredient mix to it by hand and gently mix everything till combined through. At this point I like adding chocolate chunks/chips, and some cranberries or raisins too. Be your own judge and add these opt ins if you so desire. If not, proceed to the next step.
Preheat oven to 425F degrees. Line muffin tin with baking cups or spray with nonstick spray. Set aside.
Make the streusel by mixing ingredients together. Now fill the muffin pans 3/4 to the top, Sprinkle the streusel on top of the muffins.
Next bake the muffins for 5 mins at 425F or 210 C. Then lower the temperature to 350F or 180C and bake for another 14-15 mins until muffins are set and lightly browned.
Allow the muffin to cool for 10 mins in the pan before gently removing it and letting it cool to room temperature.
Muffins can be stored in air tight container for a week or frozen for 2 months.