¼cupdark rum - optional; if omitting rum, you can add 1 tsp vanilla extract
Grease an 8x8 baking dish with cooking spray or butter. Cut stale brioche into 1½-inch chunks and place into baking dish. Press down gently to make sure gaps are filled.
In a saucepan over medium heat, heat eggnog, evaporated milk, eggs, butter, and sugar, whisking constantly.
Continue to cook another 10 minutes, whisking often, until slightly thickened. Remove from heat and stir in vanilla and rum.
Gently pour custard over bread chunks in baking dish, making sure to saturate each piece of bread. Press down with a spoon to make sure all of the bread is in contact with custard liquid.
Allow bread to sit for 30 minutes to soak up custard.
Preheat oven to 350°F.
Top pudding with chopped pecans.
Bake pudding in preheated oven for 45 minutes. If necessary, cover loosely with foil halfway through baking to prevent overbrowning. While your pudding is baking, make your brown butter rum sauce.
Brown Butter Rum Sauce
Melt in a light-colored large sauté pan or saucepan over medium heat. Continue cooking, stirring often, about 5 minutes or until milk solids separate and begin to turn golden brown.
Whisk in flour and continue to cook another minute.
Add in brown sugar and eggnog, and grate in nutmeg.
Cook, stirring constantly, until thickened. Stir in rum and cook another minute or so.
Serve with warm bread pudding.
Stale bread: Make sure your bread is stale. I leave mine out with each slice exposed overnight, but you can also place cubes of bread spaced out on a large cookie sheet, and heat them in the oven at 300°F for about 15 minutes, or until dried out and slightly toasted.Brown butter: Check out my How to Brown Butter Post for more details and images on how to brown butter.Storage and Freezing: This eggnog bread pudding will keep in the fridge in an airtight container for about 3 days. It can also be frozen, wrapped well, for up to 2 months.