Cake decorating can be both enjoyable and lucrative. I know a 'sister' who recently started doing that on the side. Of course she was faced with the classic J-dub dilemma, birthday and holiday cakes and pastries. Needless to say she has cut back on what could have been a profitable side job for her.
This brings me to my next point, make sure you mix in a few business type courses. Marketing, small business and sales can help you push along your venture. You can be the best at what you do, but you have to know how to promote yourself. Thats not mine I got it from the rich dad poor dad book.