In a bowl, whisk together flour, baking soda, baking powder, salt, sugar, brown sugar and cinnamon. Add in egg yolks and streak in milk and vinegar until a smooth batter has formed. Fold in egg whites.
Heat an ebelskiver pan to medium heat, and brush with melted butter. Sprinkle with 1/2 teaspoon of sugar, and scoop 2 tablespoons of the batter into each hole. Cook for 1-2 minutes until batter starts to pull away from the sides.
Using toothpicks or thin chopsticks, gently flip each pancake, and continue to cook for another 1-2 minutes until golden.
If cooking one of the variations, add half the amount of batter followed by mix-in ingredient(s), and seal with remaining batter, making sure to cover the mix-in.
To make the banana cream filling, mash banana and brown sugar in a bowl until smooth. Mash in cream cheese, mixing until smooth. Stir in vanilla pudding and maple syrup. Place mixture in a piping bag and refrigerate until ready for use.