Place butter and brown sugar in the oven and stir until well mixed.
Place the pineapple slices in the butter and sugar mixture in the bottom of the oven.
In a separate bowl, mix the cake mix and the egg. Pour this batter over the pineapple
in the oven, then put the lid on the oven and bake about 30-40 minutes. Test the
cake for doneness with a straw or wooden pick.
When the cake is done, remove the coals from the oven, remove the lid and let
the oven cool for about 10 minutes.
Using a large cutting board or a piece of cardboard,
covered with wax paper, hold the board on top of the oven and invert the oven quickly.
This will allow the cake to fall on the board and the pineapple will be on the top.
A safer way to support the cake when you invert it is to cut the cardboard in a
round piece the same size as the cake, and it will fit inside oven on the cake;
then when the oven is inverted, the cardboard can be held directly under the cake.