I do think it should have more contrast when it comes to its values. Make the background more dark in value than your subject. After that, modify your cast shadows, intensify it as per your need. (Not sure what's your target though but value adjustment is a good start!) A good method to determine if your composition is reading well is to just blur or squint your eyes! When I blur my eyes, the point of interest (the cake) is not really reading well. I do like the illustration overall, that seems a very delicious cake!