Butter a 9x13 casserole dish with the 2 tablespoons of butter. Beat together eggs, half and half, milk, sugar, vanilla, cinnamon and nutmeg. Dip each slice into the egg mixture then layer bread slices in pan in 2-3 layers. Pour remaining egg mixture over bread slices and between the gaps. Combine remaining ingredients - butter through nutmeg - in a food processor and pulse until nuts are chopped and ingredients are well combined. Sprinkle over the top of the casserole. Cover and refrigerate overnight.
Preheat oven to 350 degrees F. Bake uncovered until puffed up and golden and eggs are cooked, about 40 minutes. Serve with maple syrup.
Recipe by Cooking With MicheleĀ® at https://cookingwithmichele.com/2011/05/french-toast-casserole/