For the bread: Heat oven to 350 degrees. Generously grease a loaf pan.
Cream the butter, maple syrup, eggs, pumpkin, and vanilla in a large bowl. Usa a separate, large bowl and a wire whisk to mix the flour, baking soda, pumpkin pie spice, cinnamon, and salt. Stir in the pecans.
Fold the wet ingredients into the dry ingredients until barely incorporated - do not over mix. Spoon batter into greased loaf pan. Bake until a toothpick inserted into center of the loaf comes out clean, about 1 hour. Cool the bread for 15-20 minutes on a wire rack, then remove the loaf from the pan to cool the rest of the way.
For the frosting: Cream all of the ingredients together well. Instead of frosting the entire loaf, I like to cut slices and then frost individual slices.