Preheat oven to 400 F and grease muffin pan
In a bowl, mix flour, baking powder, salt, sugar, and cocoa powder
Using food processor, mix oil, sugar, vanilla, eggs, and banana, then pour mixture into dry ingredients, mix until just combined
Divide batter and sprinkle top with grated lemon peel
Bake for 18-20 minutes
As soon as taking out the pan, push in white chocolate on muffin
Yummo!