Preheat the oven to 425 degrees F.

Sift the self-rising flour, cake flour, baking powder, baking soda, sugar, and salt into a large bowl. Using your fingers or a pastry cutter, work the 4 tablespoons cold butter into the flour until the pieces are pea size. Add the bacon, Cheddar and green onions to the flour mixture. Pour the heavy cream into the flour mixture and, with your hands or a rubber spatula, stir just until the cream and flour come together to form a dough. Sprinkle some of the all-purpose flour on a work surface and place the dough on top of the flour. Using your hands, press the dough into a 1/2-inch thick disk about 8 inches in diameter. Using a 3-inch round cutter dusted with flour, cut out 6 dough rounds. Be sure to press straight down when cutting the dough, (a twisting motion will prevent the dough from rising).

Use 2 tablespoons of the melted butter to brush the insides of a cast iron pan. Place the biscuits into the pan and brush the tops with the remaining tablespoon of melted butter. Bake in the oven for 15 to 20 minutes, or until golden brown. Allow to cool briefly before running a thin, sharp, small blade around the edge of the biscuit pan and inverting the pan to release the biscuits.