Preheat oven to 350 degrees, butter a 9x5 loaf pan.
Beat the melted butter and brown sugar in a medium bowl until well incorporated. Add the sweet potato, maple syrup, eggs, milk and vanilla. Beat until well incorporated.
Sift the flour, baking soda, baking powder, cinnamon,salt and nutmeg together. Make a well in the center of the four, add the sweet potato mixture and 3/4 cup pecans, stir together until just incorporated.
Pour and spread the mixture evenly into your prepared pan. Sprinkle 1/2 cup pecans evenly over the top of the batter. Bake 50 - 60 minutes until done or tests done with a toothpick. Cool for about 15 minutes before removing loaf from the pan to a cooling rack.