Preheat oven to 350 degrees (F)Combine the melted butter, eggs, almond milk, pumpkin puree, and maple extract in a blender and blend until smooth.Combine the almond flour, coconut flour, sweetener, baking powder, salt, and spices in a medium bowl and stir well.Pour the blender ingredients into the dry ingredients and stir until well combined and moisture is absorbed.Stir in the nuts if using.Line a long, narrow loaf pan with parchment paper and spoon the batter into the pan. Sprinkle with additional nuts if desired.Bake the bread at 350 degrees (F) in the center of your oven for 60 minutes (or until a knife inserted in the center comes out clean.)Turn off the oven and leave the bread in there for an additional 15 minutes.Remove the bread from the oven and then from the pan using the parchment paper base to lift it out.Cool on the counter or in the refrigerator loosely covered for a minimum of 4 hours, but for best results leave it overnight before slicing.