1. Coat 2 baking dishes, 13 x 9 x 2 inches, with nonstick cooking spray.
2. Slice bread into 12 equal slices, about 1 inch thick. Arrange slices in prepared dishes.
3. In large bowl, beat together eggs, half-and-half, milk, vanilla, nutmeg and salt. Pour mixture over the 2 baking dishes, dividing equally. Cover and refrigerate 4 hours or overnight.
4. Heat oven to 350 degrees F.
5. In saucepan, melt butter. Stir in brown sugar and pecans until combined. Spoon evenly over all bread slices.
6. Bake at 350 degrees F for 30 to 40 minutes or until lightly browned.
7. Dust with powdered sugar and serve warm.