Combine the cream cheese, sugar and vanilla extract in the mixer bowl. Beat until smooth; set aside.
Banana and Walnut Topping:
Dry toast the walnuts in a small pot for 2 minutes. Carefully add syrup to nuts bring to a light boil, add half and half stir to combine. Add bananas. Keep warm over low flame.
In a wide dish, combine the milk, eggs, lemon zest, salt, and vanilla extract. Beat with a fork until well blended. Pour enough vegetable oil into a large skillet to cover by 1/8 inch. Dip the bread slices into the egg mixture, and moisten thoroughly on both sides. Add several bread slices to skillet and cook for 2 to 3 minutes on one side or until deep golden brown. Flip; continue cooking on other side until deep golden brown and slightly puffy throughout, 2 to 3 minutes. Transfer bread slices to paper towels to remove excess oil. Place in a warm oven while preparing remaining slices. Repeat with remaining bread slices, adding more oil if necessary. Cover half of the slices of toast with 1/4 of the Cream Cheese Filling. Place the remaining slices on top of the cream cheese-covered ones, forming sandwiches. Cut on an angle. Pour warm Banana Walnut topping over toast.