In a large mixing bowl, combine the warm water and sugar, stirring until the sugar dissolves.
Sprinkle the instant yeast over the water mixture and let it sit for about 5 minutes until it becomes frothy.
Add the melted butter, kosher salt, and all-purpose flour to the yeast mixture.
Mix until a dough forms, then knead the dough on a floured surface for about 8-10 minutes until it is smooth and elastic.
Place the kneaded dough in a greased bowl, cover it with a damp cloth, and let it rise in a warm place for about 1 hour or until it has doubled in size.
Once risen, punch down the dough to release the air, then shape it into a loaf.
Place the shaped loaf into a greased loaf pan and cover it again with the damp cloth.
Let it rise for another 30-45 minutes until it has risen above the edge of the pan.
Preheat the oven to 350°F (175°C).
Bake the bread for 30-35 minutes or until the top is golden brown and sounds hollow when tapped.
Remove the bread from the oven and let it cool in the pan for a few minutes before transferring it to a wire rack to cool completely.
