Place rack in the bottom of any size CanCooker and add 12 oz water. In a large bowl beat cake mix, water, vegetable oil and 3 eggs until combined. In a separate bowl mix 1 egg, cream cheese and powdered sugar together until smooth and creamy. Pour carrot cake batter into mini loaf pans ¾ full then spoon in cream cheese mixture on top. Take a knife or handle and swirl cream cheese mix into carrot cake batter to get a marbling appearance. Place mini loaf pans on the rack, close lid and steam for 25 minutes on low medium heat. Let stand for 5 to 10 minutes, cool completely before cutting. Sprinkle with powdered sugar if desired.