In a small bowl, combine brown sugar and cinnamon; set aside.
Put butter in a microwave safe bowl and microwave, in 20 second increments, stirring in between, until melted.
Remove from microwave and add 1 cup brown sugar; stir until well incorporated.
Pour into bottom of a greased 9 × 13-inch pan, spreading mixture evenly.
In a medium bowl, beat eggs, milk, and vanilla until incorporated; set aside.
Lay a single layer of Texas Toast in pan, cutting pieces to fit if needed.
Spoon 1 cup of egg mixture evenly over bread.
Sprinkle with half of the brown sugar and cinnamon mixture.
Repeat with second layer, using up the rest of egg mixture over that layer, ending with a sprinkling of brown sugar and cinnamon mixture.
Try to get the custard evenly soaked into the bread slices.
Cover tightly and chill overnight in refrigerator.
When ready to serve, pre-heat oven to 350°F.
Remove French Toast from refrigerator, leave covered, place on lower rack, in pre-heated oven and bake for 40 – 45 minutes.
Bake covered for the first 30 minutes, and uncovered after that.
Remove from oven and sprinkle with confectioners' sugar.
If desired, serve with pure maple syrup.
