Preheat the oven to 400°F (200°C).

Peel and slice the yams into 1/4 inch thick pieces.

Place the yam slices in a 12x12 inch baking pan.

Pour water and vanilla extract over the yams.

In a small bowl, mix the softened butter, granulated sugar, light brown sugar, cinnamon, and allspice until well blended.

Sprinkle the sugar and spice mixture evenly over the yams.

Cover the baking pan tightly with a lid or aluminum foil.

Bake for 45 minutes.

Remove the cover and sprinkle raisins and pineapple chunks over the yams.

Baste the yams with the juices in the pan.

Cover the pan again and continue baking until the yams are very tender and the juices are bubbling, about 20 minutes more.

Serve warm directly from the baking pan.