Prepare the bread. Preheat the oven to 350°F. Cut the bread loaf into even 1-inch pieces.
Make the egg mixture. In a bowl, whisk together the eggs, milk, heavy whipping cream, maple syrup, sugar, vanilla, and cinnamon. Stir in the chopped pecans.
Combine. Arrange the bread pieces in a deep casserole dish. Pour the egg mixture evenly over the bread and gently toss until all the pieces are coated. Sprinkle the whole pecans over the top.
Bake. Cover the casserole dish with foil and bake for 20 minutes. Remove the foil and bake for another 15–20 minutes, or until the bread is golden and the casserole is set.
Make the glaze. While the casserole bakes, melt the butter and maple syrup in a saucepan. Remove from the heat and whisk in the powdered sugar and heavy whipping cream until smooth and thick.
Glaze. Drizzle the glaze over the warm French toast casserole.
Serve and enjoy, friends!