Banana muffin

When I flipped through my recipe collection, here I found, one of the greatest muffin recipe which results in a mouth watering banana muffin:) I'm not being exaggerated or over reacting here, this is true, this is the banana muffin everyone is looking for! It's moist and fluffy, with a great amount of banana flavor, jumbo size, sugar coated top, what else could you say for this one little amazing muffin?
Banana Muffin Recipe
(make 6jumbo muffins):
1/3cup butter, soften in room temp.
1/2cup packed brown sugar
1/4cup white sugar (plus extra for toppings)
1egg
1tsp vanilla
1/4cup buttermilk (or sour milk)
1/2cup banana puree (mashed about 1large banana)
1 1/4cup flour
1tsp baking powder
1/4tsp salt
1/4tsp baking soda
1/8tsp ground cinnamon

1) Line a muffin tin with 6paper cups, preheat oven to 475F!!!
2) by using the creaming method, beat together butter and both sugars until light and creamy. Add in egg and vanilla, beat until combined. Then add in the milk and banana purée, just stir until everything corporate.
3) in a separate bowl, mix together the flour, Bp, bs, salt and cinnamon. Then add to the wet mixture and stir until just combined. (may add nuts/chocolate chips /dry fruits according to your personal preference )
4) pour batter into the muffin cups, fill them to the top, pls :) sprinkle sugar and pop them into the oven. Bake at 475F for 10mins, then reduce temp to 350F and continue to bake for another 10mins. Watch your muffin carefully, don't let them to get burnt.