Boil one sweet potato per person (smaller is better and try and get them all the same size) until they are tender (~30 min)

Let cool and peel off skin (hands are enough)

Cut into 3/4? slices (20mm for everyone else in the world)

Cover an oven safe pan (I use cast iron skillet) with the potatoes making a couple or 3 layers.

Put pineapple chunks on top and then cut thin pats of butter and go over that. Then sprinkle with a generous amount of brown sugar and a bit of either pumpkin pie spice, nutmeg, cinnamon, or whatever floats your boat.

Put uncovered in a hot oven with enough flame to caramelize the sugar and char the pineapple a bit. Takes maybe 20 minutes.