In a large resealable plastic bag, add the flour, sugar, salt, and active dry yeast. Seal the bag and shake vigorously to combine the dry ingredients.
Pour the warm water and vegetable oil into the bag with the dry ingredients. Seal the bag and gently knead and squeeze the mixture through the plastic until a sticky dough forms and the ingredients are evenly hydrated.
Leave the sealed bag in a warm spot and let the dough rise inside the bag until doubled in size, about 45 to 60 minutes.
Grease a 9x5-inch loaf pan. Open the bag, transfer the dough into the pan, shape the top gently with damp hands, and cover with a clean towel. Let it rest for 20 to 30 minutes for a short second rise.
Preheat the oven to 350°F. Bake the loaf for 25 to 30 minutes, or until the top is golden brown and an inserted toothpick comes out clean.
Remove the bread from the oven and let it cool in the pan for 10 minutes, then transfer to a wire rack to cool completely before slicing.
Notes
For best texture, allow the loaf to cool completely before slicing. Dough can be mixed in advance and refrigerated for a slower rise.