Make the corn bread: In a bowl, stir together the flour, cornmeal, baking powder and salt. In a small bowl, whisk together the milk, egg and butter and stir the mixture into the cornmeal mixture, stirring until the batter is just combined. Pour the batter into a greased 8-inch square baking pan and bake the corn bread in the middle of a preheated 425 degree F. oven for 20 to 25 minutes, or until a tester comes out clean. Let the corn bread cool in the pan for 5 minutes, invert it onto a rack, and let it cool completely. Crumble the corn bread coarse into 2 shallow baking pans and toast it in the middle of a preheated 325 degree F. oven, stirring occasionally, for 30 to 35 minutes, or until it is dried and deep golden. The crumbled corn bread may be made 3 days in advance and kept in an airtight container.

In a large bowl, whisk together the eggs, milk, cayenne and salt to taste, add the crumbled corn bread, tomatoes and scallions and combine the mixture well. Divide the corn bread mixture between 2 greased 9-inch round cake pans, let it stand for 15 minutes and bake the pudding in the middle of a preheated 375 degree F. oven for 40 to 45 minutes, or until it is golden. Cut the pudding into wedges.