Grease a 9x13-inch baking dish.
Cut cinnamon swirl bread into 1-inch cubes and spread evenly in the prepared dish.
In a large bowl, whisk together 6 eggs, 2 cups whole milk, 1/2 cup heavy cream, 1/2 cup granulated sugar, 1 tablespoon vanilla extract, 2 teaspoons ground cinnamon, and 1/4 teaspoon ground nutmeg.
Pour the egg mixture evenly over the bread cubes, pressing the bread down gently to soak up the custard.
In a small bowl, mix together 1/2 cup melted unsalted butter and 1/2 cup brown sugar.
Drizzle the butter and brown sugar mixture over the bread cubes.
If using, sprinkle 1/2 cup chopped pecans on top.
Cover the dish with aluminum foil and refrigerate for at least 30 minutes, or overnight.
Preheat your oven to 350°F (175°C).
Bake the covered French toast for 25 minutes.
Remove the foil and bake for an additional 15-20 minutes, until the top is golden brown and the center is set.
While the bake is in the oven, prepare the cream cheese glaze.
In a medium bowl, beat 4 oz softened cream cheese until smooth.
Gradually add 1 cup powdered sugar to the cream cheese and mix until combined.
Mix in 2 tablespoons milk and 1/2 teaspoon vanilla extract until the glaze is smooth and pourable.
Drizzle the cream cheese glaze over the warm French toast bake.
Dust with powdered sugar for extra sweetness, if desired.
Serve warm and enjoy!