Preheat oven to 350 degrees F. Grease a 12-count muffin tin with butter or non-stick cooking spray. Set aside.
In a large mixing bowl whisk together the whole wheat flour, all-purpose flour, baking powder, baking soda, brown sugar, and ground cinnamon. Set aside.
In a separate, smaller bowl, whisk together the eggs, oil, vanilla extract, and coconut milk.
Add the egg mixture to the flour mixture and gently combine with a rubber spatula until approximately half combined.
Add the mashed over-ripe bananas, white chocolate chips, and 1 cup frozen raspberries to the batter and fold together to combine. Do not over-mix.
Divide the batter evenly among the prepared muffin tin. Top each muffin with one banana slice, frozen raspberries, and additional white chocolate chips, if desired. Sprinkle with brown sugar and bake for 15-20 minutes, or until a toothpick inserted into the center comes out clean.
Remove from the oven and allow muffins to cool in the tin for 5 minutes before transferring to a wire rack to cool completely.