Step 1

In a small heavy saucepan melt brown sugar and water over moderate-low heat, stirring, until smooth and melted, about 1 minute, then pour into a 13 x 9-inch baking dish coated with cooking spray.

Step 2

Arrange bread slices in one layer in baking dish, squeezing them slightly to fit.

Step 3

In a large bowl whisk together eggs, egg substitute, milk, vanilla, rum, 1/2 tsp cinnamon, and salt until combined well and pour evenly over bread.

Step 4

Cover and refrigerate at least 8 hours or overnight.

Step 5

Preheat oven to 350° F. and bring bread to room temperature.

Step 6

Bake uncovered, in middle of oven until puffed and edges are pale golden, 40 to 50 minutes.

Step 7

Top with cinnamon and powdered sugar.