Cube up the French bread into 1-inch pieces.
In a large bowl, whisk together the eggs, milk, heavy cream, sugar, vanilla, cinnamon and salt.
Add the cubed bread into the egg mixture and stir gently to combine.
Fold in blueberries.
Spray a 12-cup muffin tin with non-stick cooking spray.
Scoop the mixture into each well. Press mixture into well. Top with more blueberries, if desired.
Cover with plastic wrap and place in fridge for 2 hours or overnight.
Make the walnut streusel. Combine the butter, flour, brown sugar, walnuts, salt and cinnamon. Mix with your hands until you have a crumbly mixture. Cover and place in the fridge.
When ready to bake, preheat oven to 350°F
Sprinkle with streusel mixture on top of the muffins.
Bake for 25-30 minutes or until tops are golden brown. Cool for 5-10 minutes.
Run a butter knife around the muffin to remove them from the pan. Serve with your favorite French toast toppings: butter, maple syrup, powdered sugar, whipped cream, if desired.