Butter a 9- by 12-inch (or similar) baking dish.

In a large bowl, combine the eggs, 2 cups milk, heavy cream, sugar, and vanilla. Whisk well. Add the bread and stir well to combine. Pour into the prepared baking dish, cover, and refrigerate overnight or for at least 4 hours.

Preheat the oven to 350 degrees and take the bread out of the fridge to sit at room temperature while the oven is preheating. Prepare the topping by combining the flour, walnuts, brown sugar, cinnamon, salt, and nutmeg in a medium mixing bowl. Add the butter and work into the flour mixture with your fingers or a pastry cutter until it resembles fine pebbles. Sprinkle over the top of the bread. Bake uncovered for 50-60 minutes or until browned and set.

Prepare the cream cheese drizzle by combining all ingredients except the milk in a small saucepan. Warm over low heat until melted and stir until smooth. If too thick, add milk, a little at a time. Drizzle while warm over the warm French toast.