Make Cream Cheese Filling: In a medium bowl, beat softened cream cheese with electric mixer for 1 minute until completely smooth. Add powdered sugar and vanilla extract, beating another 30-45 seconds until mixture is smooth and spreadable. Set aside.
Assemble Sandwiches: Lay out 12 slices of Texas Toast. Spread about 2 tablespoons cream cheese filling evenly over one side of 6 slices, going all the way to edges. Top each with remaining bread slices to form 6 sandwiches.
Prepare Custard: In shallow dish, whisk together eggs, milk, sugar, cinnamon, and vanilla until completely uniform with no streaks.
Cook French Toast: Heat large skillet over medium heat and add 1 tablespoon butter. Dip one sandwich in egg custard for 5-10 seconds per side to coat. Place in skillet and cook 3-4 minutes per side until deep golden brown.
Continue Cooking: Transfer cooked French toast to serving plate or keep warm in 200°F oven. Repeat dipping and cooking with remaining sandwiches, adding more butter to skillet between batches as needed.
Serve: Serve immediately while hot, topped with your choice of powdered sugar, maple syrup, fresh berries, whipped cream, or other desired toppings.