Preheat the oven to 350. Line a muffin tin with liners.
Whisk together the flours, baking soda, salt, and cinnamon. Set aside. In a large mixing bowl, cream together the sugar and butter. Add eggs one at a time, combining completely after each addition. Add the mashed banana, yogurt, and vanilla. Slowly add the flour mixture and beat until just combined (don't over-mix).
Divide the batter evenly (so the cups are about 2/3 full) among muffin tins. Combine the chopped pecans and brown sugar and sprinkle them on top of the batter. Bake for 23-28 minutes or until a toothpick inserted into the center of a muffin comes out clean. Remove from oven and allow to cool for 5-10 minutes and then transfer to a cooling rack and allow to finish cooling. Serve with breakfast or as a snack.