Melt the butter in a saucepan over medium heat and stir in the brown sugar and syrup. Turn the heat up to medium-high and bring it to a simmer, cook, stirring until the sugar is melted. Pour it into the prepared pan.
Sprinkle with the pecans and top with the bread. Lay it down from edge to edge touching each other.
In a medium bowl whisk together the eggs, milk, vanilla and salt. Pour it over the bread.
Cover the pan with foil and refrigerate overnight or up to 24 hours.