Preheat oven to 350°F.

In a medium-sized bowl, combine sweet potatoes, eggs, butter, brown sugar, and spices. Mix well. Divide mixture evenly into the ramekins.

In a medium-sized bowl, add egg yolks and sugar. Stir for 1 minute. Next add the cream and vanilla. Mix well. Pour mixture evenly over the sweet potato mixture.

Place the ramekins in a larger baking dish and pour water into the larger dish until it is about an inch deep.

Bake at 350° for 40 minutes, or until a knife inserted in the center comes out almost clean. Carefully remove pan from the oven and remove the ramekins from the water. Allow them to cool. Once cool, cover with foil and refrigerate for several hours or overnight.

Before serving, remove them from the refrigerator and sprinkle 1 teaspoon sugar evenly over the top. Using a kitchen torch, carefully melt the sugar.