Betty Boop is hand painted on fondant.  If you are not a good artist you can still pull off a cake like this.  First find the picture you want to make.  Cut it out and lay it on the fondant.  Cut out the basic shape.  Then cut the individual parts of the cake, eyes and hair separately.  Place them on the fondant and with a diluted solution of coloring gel and clear vanilla extract draw in the lines.  Now all you have to do is to fill in the blanks.  Think of this like a coloring book image.  Adds some festive sprinkles are your are all set to surprise everyone with your cake.