If burger buns come out dense or dry, it's likely because too much flour was added. This often happens when bakers measure by volume, with measuring cups, because it's so easy to pack extra flour into those cups and end up using more than is necessary. For a soft bun, make sure to measure the flour by weight (in grams, with a kitchen scale) to ensure accuracy. If you don't have a kitchen scale, use the scoop and level method to measure your flour (and add it a little at a time until the dough looks just right!)