In a large mixing bowl, whisk the buttermilk, eggs and vanilla together until well combined. In a separate bowl, mix together the flour, baking powder, baking soda, salt and granulated sugar. Combine the wet ingredients with the dry, and stir with a spoon to get rid of lumps. Fold in the ground pecans and most of the melted butter, and whisk until the batter is smooth.
Heat a griddle or skillet over medium-low heat; swirl in a little melted butter to keep the pancakes from sticking. In batches, ladle the batter onto the griddle. When just set, lightly press the bananas into the batter. Continue cooking until the pancakes are golden on the bottom and small bubbles appear on the surface, about 2 minutes more. Flip and cook until golden on the reverse side, another 3 minutes. Transfer the pancakes to a warming plate in the oven while you make the rest.
To serve: Stack the pancakes on plates, then slice the maple butter and layer it between stacks. Place in the oven for 1 1/2 minutes to melt. Dust with confectioners' sugar and sprinkle with candied pecans. Serve hot.
In mixing bowl, mash the butter, maple syrup and honey together with a rubber spatula until well blended. Transfer to parchment or wax paper, roll in to a log, and twist the ends. Chill in the refrigerator for 30 minutes.