One of the recipes I've used before does call for boiling the potatoes whole with their skins on, to impart that earthiness, then scraping the skins off after they've cooled a bit.Baked potato mash gives a wonderful flavour but takes an age to make. It involves baking spuds, scooping out the flesh then putting the skins in a pan with milk and warming it through to infuse the flavour before using the strained milk to complete the mash with butter and seasoning.