Poke holes in yams with a fork. Wrap in foil. Bake for 45-60 minutes until soft.
While the yams are roasting, place a small pan over medium heat. Add the butter. Once melted, add sage leaves and cook until they are crispy, about 1 to 2 minutes per side. Remove them with a slotted spoon and place on a paper towel to drain. Then crumble the sage leaves.
Peel the cooked yams and place in a deep bowl. Using a hand mixer, whip until smooth. Add juice from the oranges, maple syrup, goat cheese, salt and crumbled sage leaves. Whip together until smooth.