Place the water into a large mixing bowl, then whisk in the sugar and yeast. Let the mixture sit for five minutes while you gather your other ingredients, until it becomes frothy.
Whisk in the butter and salt.
Begin stirring in the flour, ½ cup at a time. You can start working in the flour with your hands when the mixture gets too thick to stir. Once you've added all 2 ½ cups of flour, the mixture should have turned into a shaggy dough.
Lightly sprinkle a work surface with flour. Turn the dough onto the surface, then knead it for 5 to 8 minutes, until it becomes smooth and elastic.
Lightly coat the inside of a large mixing bowl with vegetable oil or vegan butter. Shape the dough into a ball and place it in the bowl. Cover it with a damp tea towel or plastic wrap, and place the bowl in a warm location.
Let the dough rise until it has doubled in size, which should take 1 to 2 hours, depending on the temperature (Note 1).
Lightly oil or butter the inside of an 8 x 4 inch bread pan.
Punch the dough down, then place it on a lightly floured work surface. Gently roll the dough into a log, shaping it to fit inside of your bread pan. Place the dough into the pan, seam side down.
Cover the pan with a damp tea towel or plastic wrap, then place it in a warm spot. Let the dough rise a second time, until it has gotten puffy but not quite doubled in size, about 45 minutes to an hour.
Preheat the oven to 350°F.
Place the pan into the oven and bake the bread until the top is golden brown, 30 to 35 minutes.
Place the loaf pan on a cooling rack and let the bread cool for ten minutes. Remove the bread from the pan and transfer the loaf to the cooling rack. Let it cool completely.
Slice the bread, then serve.