holiday rum hot cake, or magic floating cakes

This recipe is pretty weird. It's not weird tasting, its just a really weird process, at least to me. It's from a Nigella Lawson cookbook, but adapted gluten free, and made into individual servings because I don't have a good 9" baking dish. It's a cake, but floating in a caramelly sauce. It's good alone, or with whipped cream. It's pretty fast, and impressive. I made it for Christmas at my mom's.

Holiday rum hot cake
2 c water
1 c flour mix
1/2 t xanthan gum
1 1/2 c brown sugar
1 1/2 t baking powder
2 t ginger
2 t pumpkin pie spice (or other things)
1/2 c milk
1/4 c vegetable oil
1 egg
6 pats of butter
6 t rum

Preheat the oven to 425, and put a baking sheet in the oven. Put the water on to boil. Mix the flour, xanthan gum, 1/2 c sugar, baking powder, 1 t each of ginger and pie spice, milk, oil and egg to form a batter. Divide evenly between 6 buttered ramekins. Combine the rest of the sugar and the remaining teaspoon each of the ginger and pie spice. Sprinkle evenly over the batter in the 6 dishes, top with pats of butter, and 1 tsp rum each.
By now your water should have boiled, pour the boiling water over the batter sugar butter mix so each one is almost full to the top. Place on the hot baking sheet and bake for about 20 minutes, then let rest 10.