Bring the water to a boil in a medium saucepan. Add the brown sugar, molasses, Cajun spice, and salt, and stir occasionally until the sugar is dissolved, about 5 minutes. Remove the saucepan from the heat and allow the mixture to cool. Once the mixture is cool, transfer the liquid to a large bowl and add the sausage, and cover the bowl and marinate in the refrigerator overnight.
Remove the sausage from the marinade and reserve 2 ounces or 1/4 cup marinade. In a medium skillet, add the sausage and marinade. Cook the sausage over medium-high heat for about 6 minutes, turning frequently to allow the sausages to cook on both sides. Let the liquid reduce to a glaze consistency and serve the sausages hot. Serve the sausages with honey mustard or desired condiment.