Sift the buckwheat flour, tapioca starch, and baking powder into a large mixing bowl and whisk to combine. Use a spoon to create a well in the center of the flour mixture and then set aside.
In a small bowl whisk the mashed banana with the applesauce. Pour the banana mixture into well of flour and begin whisking gently while gradually pouring in the milk. Whisk the wet ingredients in the center of the flour mixture, allowing the wet ingredients to gradually pull more flour from the sides of the bowl into the center. Once flour is completely incorporated into wet ingredients, set aside.
Heat a drizzle of oil or butter in a frypan on a medium heat. Once the frypan is hot enough add the first batch of pancakes (about ⅓ cup of batter per pancake).
Flip the pancakes once bubbles start to rise to the surface and cook on second side until golden brown. Transfer cooked pancakes onto a plate lined with a clean tea towel and cover to keep warm while cooking remaining pancakes.
Serve straight away with desired toppings.