-Preheat oven to 350°, spray the muffin pan with non-stick baking spray if needed.
In a food processor combine the butter, flour, brown sugar, cinnamon, and salt. Pulse until combined, and the mixture forms into small pea sized pieces.
Remove the blade, and set aside. Add the oats, and walnuts, mixing with spoon or spatula until well combined. Place in the refrigerator until ready to use.
Cube the bread, place in a large bowl, and set aside.
In a large mixing bowl combine the eggs, milk, cream, and vanilla and whisk until well combined.
Then pour over the cubed bread, and add the blueberries. Gently fold until blueberries are evenly combined in mixture.
Spoon the mixture into the muffin cups, and spoon the streusel over the tops of all the muffins.
Bake for 25-30 minutes. Let rest for 3-5 minutes, then serve with a touch of maple syrup.