To the warm water in a large bowl add the maple syrup and yeast. Allow to sit until starting to foam--about 8 to 10 minutes.
Once foaming, add the butter and stir to combine. Add the flour and salt and stir to combine. Transfer to a floured surface and knead until the dough is smooth and elastic--about 14 minutes. If adding raisins or nuts knead them in during the last five minutes.
Place it back in the bowl and brush with oil to prevent drying out. Cover with plastic wrap or a damp towel and allow to rise in a warm place until doubled in size. About 1 1/2 hours. Longer if you added raisins or nuts.
Once doubled, transfer to a floured surface and roll to a 9x9 square. In a small bowl blend the brown sugar, white sugar and cinnamon. Set aside. Brush the dough with melted butter, egg wash or just water, and sprinkle on the cinnamon sugar.
Startig on one end, roll up and pinch the seam well to seal. Pinch the ends closed as well.
Transfer to a greased and parchment paper lined 9x5 loaf pan. Rise uncovered in a warm place until 2" above the rim of the pan--about an hour or so.
Bake at 450 for 25 to 27 minutes, tenting with foil if the bread starts to get too dark.
Once baked transfer to a cooling rack to cool completely.
Blend powdered sugar, vanilla and milk and use a fork to drizzle over the bread.
Bread will last up to 3 days tightly wrapped on the counter or may be frozen for up to 2 months.