Cut the brioche into 1-inch bite size cubes. It's best to use somewhat stale bread to prevent a soggy casserole, so I like to pop in the oven at 300°F for ~10-15 minutes if I don't have any stale bread lying around.
1 loaf (1 lb.) day old brioche bread* cut into 1-inch cubes
Add the melted butter to the bottom of a 9x13 inch casserole dish and set aside.
3 Tbsp. melted butter
In a large mixing bowl, whisk together the eggs, pumpkin, milk, heavy cream, all of the spices, brown sugar and vanilla extract.
8 large eggs, 1 cup 100% pure pumpkin puree (not pumpkin pie mix), 1 cup whole milk, 1/2 cup heavy cream, 1 recipe pumpkin pie spice mixture*, 1/4 cup dark brown sugar, packed, 1 Tbsp. vanilla extract
Arrange the stale bread cubes into casserole.
Pour the egg custard over the bread and gently press the bread down so it's mostly covered. Cover & refrigerate for at least 30 minutes or overnight.
Combine the flour, brown sugar and cinnamon together. Cut in the butter using a pastry cutter or fork (but honestly I just use my hands to do this!) until mixture is crumbly. Refrigerate this too, separate from the casserole.
1/2 cup all purpose flour, 1/2 cup dark brown sugar, packed, 2 tsp. ground cinnamon, 1/4 cup cold butter, cut into cubes
When ready to bake, preheat the oven to 350°F. Sprinkle the streusel on top of the casserole and top with chopped pecans. Bake for 35-40minutes or until the middle is set. Tent with foil if tops get browned at all. Remove from oven and let sit 5-10 minutes.
1/2 cup chopped pecans
Make the maple glaze by mixing all ingredients together in a medium sized mixing bowl until smooth. Taste and add more maple syrup or cream as desired.
2 cups powdered sugar, 4 Tbsp. melted butter, 2 tsp. pure maple syrup, 1-2 Tbsp. heavy cream, 1/2 tsp. vanilla extract, pinch of salt