Wash, peel and slice the sweet potatoes into ½ inch medallions.
Melt butter in a large skillet on the stovetop over medium heat.
Turn the heat to low and add the brown sugar, stirring until it dissolves. Stir in orange juice and spices. Allow the mixture come to a low simmer while stirring. As the mixture warms, the spice will dissolve fully.
Carefully add the sliced sweet potatoes to the skillet. Make sure each slice is coated with the sugar mixture on both sides. Stir every 5 minutes for the first 15 minutes, turning the potatoes over, making sure neither the sweet potatoes or the sugar is sticking to the bottom of the skillet.
Gently continue to check that the potatoes aren't sticking and stir the sugar occasionally while potatoes cook for another 10-15 minutes.
When the potatoes began to caramelize and become fork tender, add those optional cranberries if desired. Continue to cook until the cranberries begin to slightly plump (about 5 minutes).
Remove the candied sweet potatoes from the heat and allow to cool at least 5 minutes. Add the chopped pecans if desired, and serve.