Whisk together first 5 ingredients in a large bowl; add bread, tossing to coat. Let stand 30 minutes.: As the custard flavors mingle, you will notice the aroma of milk , whipping cream , and cracked black pepper lift gently from the bowl, promising a creamy interior. The reason this resting matters is that the cubed French bread loaf needs time to absorb the custard fully so that the final texture is uniformly moist and not spotty or soupy. While you wait, the bread will soften and swell, which is normal; if you skip this, the centers of the bread cubes can remain dry and undermine the custard balance. A common mistake here is rushing to bake before the bread has absorbed the liquid, which results in uneven texture. If your kitchen is cool, you may want to cover the bowl to keep the surface from forming a skin.
Preheat oven to 375°F. Spray a 9×13-inch baking dish with cooking spray.: You will sense a small shift when the oven starts to warm, the air becoming dry and carrying a hint of warmth. Preheating ensures that when the pudding goes into the oven it begins to set immediately around the edges, preventing the custard from lingering too long in a scramble like state. Using a 9×13 inch baking dish produces an even depth so the center and edges finish together; a much deeper or shallower dish alters bake time. A frequent error is not preheating, which can lengthen baking and affect texture, so always let the oven reach the correct temperature first.
Stir corn and cheese into the bread mixture; spoon into the prepared pan.: The moment you fold in the corn and shredded Asiago cheese , the mix takes on contrast, the kernels popping visually and the cheese threading through in ribbons. Stir gently so the bread pieces do not break down; you want the kernels and cheese distributed evenly for consistent bites. Spoon the mixture into the sprayed pan so the custard settles into an even layer. A potential slip up is over stirring which can make the bread paste like, so handle the mixture with a light touch.
Bake for 45 minutes or until set and golden brown.: During baking you will watch the top change from pale to a warm golden hue, and you may catch the faint waft of toasty bread and melted cheese. The center should be set so that it jiggles slightly but does not look wet, and a knife inserted near the center should come out mostly clean. This final bake transforms the custard from liquid to a tender, sliceable pudding; the timing is designed to give a browned top while ensuring a creamy interior. Over baking can dry it out, so if the edges are browned early, tent lightly with foil. A common mistake is removing it too soon, when the center is still loose, so allow a few minutes of carryover set once out of the oven.