01 - Preheat oven to 350°F (175°C). Grease a 9x13-inch baking dish with butter.
02 - In a large bowl, whisk together eggs, granulated sugar, vanilla extract, and salt until well combined.
03 - Add milk, heavy cream, cream soda, and melted butter to the egg mixture. Whisk until smooth.
04 - Arrange bread cubes in the prepared baking dish. Pour the custard mixture evenly over bread. Gently press down to ensure all pieces are soaked.
05 - Drizzle 1/2 cup caramel sauce evenly over the top and gently swirl with a knife or spoon.
06 - Let the mixture rest for 10 minutes to allow the bread to fully absorb the custard.
07 - Bake for 35-40 minutes, or until the pudding is puffed, golden brown, and set in the center.
08 - Remove from oven and let cool slightly. Serve warm, topped with extra caramel sauce and whipped cream if desired.