Spray a 9x13” baking pan with nonstick spray or line with parchment.
In a small pot over medium heat, whisk together brown sugar, corn syrup, butter and heavy cream. Once smooth, stir in 1 Tbsp vanilla and pecans, remove from heat. Pour into the bottom of the prepared 13x9 pan.
In a large bowl, whisk together eggs, milk and 1 Tbsp vanilla.
Dip both sides of each baguette slice into egg mixture. Place atop caramel in pan. Cover and refrigerate overnight.
To cook, bake in an oven heated 425 degrees for 20 minutes.
To serve, use a spatula to flip french toast upside down. Serve and enjoy!