In a small bowl, stir together the brown sugar, melted butter and corn syrup. Pour into a greased 13x9 inch baking dish, and spread evenly. Sprinkle pecans over the sugar mixture. Arrange the bread slices in the bottom of the dish so they are in a snug single layer.
In a medium bowl, whisk together the orange zest, orange juice, milk, sugar, cinnamon, vanilla, egg whites and eggs. Pour the mixture over the bread, pressing on the bread slices to help absorb the liquid. Cover and refrigerate for at least one hour or overnight.
Preheat the oven to 350 degrees. Remove the cover from the baking dish and let stand for 20 minutes at room temperature.
Bake for 35 minutes in the preheated oven, until golden brown. Dust with confectioners' sugar before serving.