This is a 9x13 cake, dirty iced with frosting, and covered in marshmallow fondant. For the collar, I used a pizza cutter to cut out a rectangle and then cut the top corners off to make pointed edges. Arrange the collar on some paper towels and prop it up with more paper towels and let air dry over night (The collar can be done in advance). The pocket is a square piece of fondant with a thin triangle piece on top. "Glue" it on the cake with water and a food safe paint brush. Place the collar on the cake and "glue" with water as well. Pipe blue frosting in shape of a tie and use an offset spatula to smooth it out. Then take yellow frosting and pipe "Happy Father's Day!" To make it look even better, get a cake box and put the cake in the box with some white tissue paper to look like a brand new shirt!