In the bowl of a stand mixer with a dough hook attachment, add the 2 1/2 cups of warm water, sugar and yeast and stir to combine. Let the mixture sit for about 4-5 minutes to allow the yeast to proof (the mixture will have bubbles).
Once the yeast is bubbly, add the butter, salt and 2 cups of flour and mix well. Mix on low speed adding the remaining flour gradually, 1/2 cup at a time mixing well after each addition. Continue to knead for about 5-6 minutes or until the dough pulls together and away from the sides of the mixing bowl.
Place the smooth dough in a lightly greased bowl and turn it over so it is completely coated with oil. This will prevent the dough from drying out. Cover the bowl with plastic wrap and let the dough rise until doubled in volume, about 1 hour.
Deflate the dough by pressing it down and turned it out onto a lightly floured surface. Divide the dough into two equal pieces and shape into loaves (basically two oblong dough balls).
Place the loaves into two lightly greased 9 x 5 inch loaf pans. Cover the loaves with a damp cloth and allow them to rise until doubled in volume, about 40 minutes.
Preheat the oven to 375 degrees Fahrenheit. Bake the loaves for 28 - 30 minutes or until the top is golden brown. Remove from the oven and immediately brush the tops with melted butter. Allow to cool for 10 minutes, then remove from the pans and cool completely on a cooling rack before slicing.