1. Generously grease 13 x 9 x 2-inch baking dish. In baking dish combine bread and KELLOGG’S POP-TARTS Frosted Brown Sugar Cinnamon toaster pastry pieces.
2. In large bowl combine eggs, milk, brown sugar, vanilla and salt. Whisk until well blended. Slowly pour over mixture in baking dish. In small bowl, stir together granulated sugar and cinnamon. Sprinkle over casserole. Cover and refrigerate for 4 to 24 hours.
3. Remove casserole from refrigerator. Let stand for 15 minutes. Tightly cover with foil. Bake, covered, at 350°F for 20 minutes. Remove foil. Bake, uncovered, at 350°F for 10 to 20 minutes more or until knife inserted in center comes out clean. Let stand for 15 minutes.
4. Meanwhile, place frosting in small food storage bag or piping bag. If using storage bag, snip off one corner of bag. Pipe frosting onto warm casserole. Serve warm.