Dice rhubarb into 10" skillet.
Top with marshmallows, sugar and red hots.
Cream butter and sugar; add eggs and beat.
Sift flour, salt and baking powder together and add to creamed mixture, alternately with 1/2 cup milk.
Pour batter over fruit.
Bake at 350 degrees for 1 hour.
Cool 5 minutes and then invert.