Pierce the skin of each sweet potato several times with the tines of a fork. Place the potatoes on a rimmed baking sheet lined with foil. Bake for about 45 minutes (time may vary depending on the size of the sweet potatoes) until very soft when pierced with a knife. Remove from oven and set aside to cool. Take skins off of the sweet potatoes and discard. Place sweet potato meat in a bowl and mash.
Heat 1/2 cup cream, butter and Roasted Garlic and Onion Jam in a small sauce pan. Add to sweet potatoes and mix until combined. Add additional 1/4 cup cream if too thick. Season to taste with salt and pepper and serve.