In a larger bowl, whisk together the whole wheat flour, all-purpose flour, brown sugar, baking powder, baking soda and kosher salt. Set aside.

In another bowl, mash the banana with a fork. Then add the egg, oil, vanilla and mix until combined, now stir in the milk.

Pour the wet ingredients into the flour mixture and whisk until the batter comes together. Let the batter sit in the bowl for 5-10 minutes.

While the batter is resting, heat a griddle over medium-high heat (I use 350°F on my griddle). Drop the batter with a small ladle or spoon onto the griddle. Cook until bubbles form and the edges are dry, about 2 minutes. Flip and cook until browned on the second side. Repeat until all the batter has been used.