Preheat your oven to 325 degrees F. Grease a 9x13-inch baking dish. Set to the side. In a large bowl, beat eggs. Add the sweetened condensed milk, sugar, butter, vanilla, cinnamon and salt; mix well. Gently stir in the cubed cake, frosting and all. It may begin to break up in the wet mixture; don't panic. It will bake up just fine. If you'd like, garnish with sprinkles. Pour into your prepared pan and bake for 50-60 minutes or until a knife inserted near the center comes out clean. Serve warm or cold.
