Set a steamer basket in a large saucepan.
Fill with enough water to come just
below basket; bring to a boil, then reduce
to a gentle simmer. Place sweet potatoes in steamer basket and cover; steam until tender, 15 to 25 minutes. Drain, and return to saucepan.
Meanwhile, in a small saucepan,
bring half-and-half, butter, and brown sugar to a simmer, stirring to combine; remove from heat. Add to drained sweet potatoes, and mash
just until smooth; season with salt and