Cook the apples: Start by peeling and dicing the apples. You'll want about 4 cups of diced apples.
Melt 1 stick of butter in a large skillet or pot. Once the butter is melted, add the apples, a few dashes of cinnamon, 1/4 cup brown sugar, and 1 tsp. vanilla extract. Stir to combine. Cover and simmer on low heat for fifteen minutes.
While the apples simmer, cut the brioche into 1" cubes. Reserve in a large bowl.
Next, warm 3 cups of milk in a sauce pan on low heat. Do not boil milk - pull it off right before it begins to boil. You want to scald the milk without boiling.
While the milk warms, and apples continue to simmer, whisk together 4 eggs, 1/2 cup granulated sugar, 1/2 cup brown sugar, 1 tsp. salt, a few healthy dashes of cinnamon (about 2 tsp. depending on how much you like the spice!), and 1 tsp. vanilla in a mixing bowl.
The milk should be warm "scalded" by now, remove it from the heat and allow to cool slightly.
Pour the milk into the whisked egg mixture. It's important to not boil the milk else it will cook the eggs. Whisk as you pour so that the mixture is thoroughly combined. Set aside.
The apples should be cooked at this point, remove them from the heat. Pour the apples into the reserved bread, stir together until thoroughly combined.
Now you'll put it all together: pour the milk/egg mixture into the bread/apple mixture and stir well. Allow the mixture to soak for 5-10 minutes, or until the bread absorbs the majority of the liquid. The mixture will be pudding-like.
Pour the pudding into a large greased baking dish. Bake at 350 F for 30-40 minutes, or until baked through and golden brown. Note: If the pudding becomes golden brown before it is baked through, simply cover and cook until it is cooked through.
Finish with a glaze or syrup, and enjoy!
For the glaze: In a small mixing bowl combine 1/2 cup powdered sugar, 1 tablespoon milk, and a splash of vanilla. Stir well and drizzle over the top of the pudding!