Put the sweet potatoes into a big kettle, cover with warm water, then boil till tender (about 7minutes, depending upon the dimensions ). Drain well & come back to the-pot. Add milk, butter, cinnamon, brown-sugar & salt into the potatoes and simmer until smooth. Use a hand mixer, even if desirable, to create them extra-smooth. Taste the potatoes & put in extra seasonings, if needed.