Preheat the oven to 350 F.
Wash the yams.
Peel, then chop the yams ( make sure that they are about 1/2 inch thick.)
Place the yams into a 9x13 bake dish.
Place the butter into a medium sized pot, then melt it over medium heat.
Once the butter is melted, sprinkle in the white & brown sugar, ground cinnamon,ground nutmeg, ground ginger, and ground clove.
Turn the stove off, mix the ingredients, then add in the vanilla extract.
Pour the candied mixture over the yams, and try to coat all the yams with the candied mixture.
Next, cover the bake dish with foil, then bake the yams in the oven for 30 minutes.
Remove the yams from the oven, and baste them with the candied mixture.
Cover the yams, and bake them for another 15-20 minutes.
Remove the yams from the oven, and let them sit for about 10 minutes before serving.