In a large bowl, whisk together buttermilk, eggs, baking powder, sugar, salt and butter.
In another large bowl mix together all-purpose flour and buckwheat flour.
Slowly add flour into the wet ingredients mixing with a whisk. Mix until there are no lumps and the batter is smooth and velvety.
In a large cast iron skillet or flat grill pan over medium-high heat, melt a tablespoon of butter. Ladle pancake batter onto skillet to desired size. Using the ladle, form pancake into circular shape. Cook on each side for 2 to 3 minutes or until golden brown. Set pancakes aside and keep warm. Repeat with remaining ingredients.
Once completed, spread peanut butter on a pancake, layer it with sliced bananas and drizzle it with honey. Top the pancake with another pancake to form a sandwich. Repeat with remaining pancakes and serve with extra honey.