After being cooked, the hot applesauce is naturally soft and tender, and it won't take much effort to mash. I like to use a regular blender for applesauce that has cooled down slightly. Traditionally, home cooks use a food mill to run the softened apples through a grate manually. A potato masher can work well for this, especially if you prefer a chunkier applesauce. An even easier method is to use an immersion blender. It can be used immediately while the applesauce is still hot, and you can pulse until the apples are just the right texture.