112 by 5-inch loaf challah, cut into eight 1-inch-thick slices
Adjust oven rack to middle position, place rimmed baking sheet on rack, and heat oven to 450 degrees. Set wire cooling rack inside second rimmed baking sheet. Place cereal in 13 by 9-inch baking dish. Whisk half-and-half, eggs, sugar, vanilla, cinnamon, and salt together in large bowl until combined.
Working with 2 slices of bread at a time, soak in half-and-half mixture until just saturated, about 15 seconds per side. Transfer soaked bread to cereal and press lightly to adhere; transfer to prepared wire rack. Repeat with remaining bread.
Add oil to preheated sheet, tilting to coat evenly. Return sheet to oven and heat until oil is just smoking, about 4 minutes. Carefully remove sheet from oven and arrange bread in even layer on sheet. Bake until exterior is golden brown and crunchy, about 20 minutes, flipping once and rotating sheet halfway through baking. Transfer toast to clean wire cooling rack and let cool for 5 minutes. Serve.