This is a perfect Christmas morning dish, whether you serve it as part of an elegant brunch or sitting around in pajamas. It is easy to put together, you do it the day before, and just pop it in the oven. It smells and tastes like Christmas and will start the day off right.
This is a really tasty dish on its own, but can be drizzled with some maple syrup or warm cranberry sauce.
In a small saucepan, melt the butter, sugar and corn syrup over medium heat, stirring frequently, until the butter is melted and the mixture is thickened and syrupy, about seven minutes. Pour ¾ of the syrup over the bottom of the baking dish, swirling and spreading it to cover.
Place a layer of bread slices over the syrup in the dish, cutting them to fit if necessary. Fill the dish as tightly as possible. Drizzle the remaining syrup over the bread, the add another of layer of bread slices.
Beat the eggs in a bowl, then add the egg nog, sugar, cinnamon, nutmeg and vanilla. Whisk together until completely combined. Pour the custard over the bread layers in the dish, pressing the bread down to be covered by the custard if it floats to the top.
Cover the dish tightly with plastic wrap and refrigerate eight hours or overnight.
When ready to bake, remove the dish from the fridge to take the chill off. Preheat the oven to 350 degrees, then bake the casserole for 35- 40 minutes, until golden and puffed and a tester inserted in the middle comes out clean. Serve warm.