In the bowl of an electric mixer combine water, yeast and 1/2 tsp granulated sugar. Whisk until yeast has dissolved and let rest 5 minutes. Stir in milk, molasses, 1/4 cup granulated sugar, salt, softened butter, nutmeg, ginger, egg and pumpkin puree until well combine. Slowly add flour and knead with a dough hook attachment until dough is smooth and elastic. Transfer dough to an oiled bowl, cover with plastic wrap and let rise in a warm place until double, about 1 hour.
Butter an 8 1/2" x 4 1/2" in pan, set aside. In a small bowl whisk together brown sugar and cinnamon, set aside. Punch the risen dough down and turn onto a lightly floured surface. Roll dough into a large rectangle, about 22" x 8." Brush with melted butter, coming within about 1/2" of the edges. Sprinkle with cinnamon mixture, coming within about 1/2" of the edges. Roll dough up jelly roll style, starting with the short side. Place rolled dough in greased loaf pan and let rise in a warm place until doubled about 45 minutes.
Bake 375 degrees for 45 minutes, tent loaf with foil halfway through baking to prevent excessive browning. Allow to cool in pan 5 minutes then remove to a wire rack to cool completely before slicing.