For the French toast:
5 cups cubed Panettone
1 ½ cups whole milk
2 tablespoons bourbon (optional)
2 tablespoons white sugar, divided
¼ teaspoon salt
¼ teaspoon ground cinnamon
¼ teaspoon ground nutmeg
1 teaspoon Pure Madagascar Bourbon Vanilla Extract
For the walnut streusel:
⅛ cup packed light brown sugar
⅛ cup all-purpose flour
1 teaspoon cinnamon
1 tablespoon butter
½ cup walnuts, finely chopped
Maple syrup, for serving
Line an 8-inch square baking pan with a foil sling sprayed lightly with cooking spray. Fill the prepared baking pan with Panettone bread cubes.
In a large bowl, beat together eggs, milk, bourbon, sugar, salt, cinnamon, nutmeg, and vanilla extract. Pour this mixture over the bread, cover tightly, and refrigerate for 8 hours or overnight.
The next day, preheat oven to 350°. In a small bowl, combine the flour and brown sugar. Using two knives or a pastry cutter, cut in the butter until you have crumbly streusel. Top your soaked bread cubes with the streusel, and bake for 38 minutes.
Remove casserole from oven, top with chopped walnuts, and bake for another 5-7 minutes, or until golden. Let cool for 10 minutes before slicing and serving with maple syrup.