1. Combine the sliced oranges and water in a large pot.
2. Bring to a boil and cook rapidly for 20 minutes or until tender.
3. Add the sugar and cook over low heat, stirring until the sugar dissolves.
4. Turn up the heat and boil rapidly about 40 minutes until the bubbling stops and the fruit becomes opaque, or until a candy thermometer reads 220°F.
5. Remove from the heat, skim the foam from the surface and let cool for 5 minutes.
6. Stir to distribute the fruit throughout the syrup. Cool completely.
Note: This can be done in advance and stored in the refrigerator for 5 days.
For the soufflé:
1. Preheat the oven to 350°F.
2. Lightly spray 4 individual ovenproof molds with a non-stick spray and lightly dust each with sugar.
3. Whip the egg whites until frothy then gradually add the sugar and salt. Beat until stiff and glossy.
4. Fold in the Blood Orange Marmalade and orange zest.
5. Turn the mixture into the sugared molds.
6. Bake for 20 minutes.
7. Remove the soufflés from the oven and dust with powdered sugar, if desired.