In a bowl, beat eggs, milk, sugar, vanilla and salt. Pour half of the mix into a 13 x 9 x 2 inch casserole dish. Arrange six slices of bread in a single layer over egg mixture. Place one piece of chocolate in the center of each piece of bread. Top with remaining bread and pour on the rest of the egg mixture. Let stand for about three minutes. (Note: If you do not have day old bread, toast it a bit to dry it out or cut down the time you let it stand in the egg mixture. You do not want the bread to get soggy because it will result in a mushy mess! Not that I would know these things first hand. But trust me on this one!).
In a large non-stick skillet or griddle, melt butter over medium heat. Fry sandwiches until golden brown on both sides. (If you do not have a skillet large enough to cook these all at once, soak them one at a time in the casserole dish so they do not absorb too much liquid.)
Remove from pan, cut in half diagonally and dust with confectioner’s sugar. Garnish with fruit if desired and watch your sweetheart savor the sweet goodness of chocolate french toast.