Preheat oven at 350(F) degrees, or 180(C) degrees. Cut Sweet Potatoes in half (length wise) and boil in water for approximately 25 minutes. Remove from heat and drain. When cool enough to handle, peel the potatoes and cut into fourths. Place potatoes in a 9x13" pan. Mix the dry ingredients and sprinkle evenly over the potatoes. Slice the 3 T Butter from the stick and then cut each T into fourths. Drop the butter evenly around the pan. Place marshmallows in the pan (3 rows of 4) Sprinkle pecans evenly over the potatoes in the pan. Pour Cream over top of the everything. Bake at 350(F) for 45 minutes or until marshmallows are golden brown. Enjoy!!!