I just used a rectangle cake and cut off the corners to make Larry. Also used a round cake to make Bob. Used remaining batter to make cupcakes to put on the Veggie Tales cake.
I used a frosting recipe found on any of the Wilton character cake pan (pdf’s can be found on their website). I made sure to keep enough out for eye/ mouth/ nose detailing, then just kept adding food coloring until I got the desired color for Bob & Larry.
I just used a larger decorating tip for the bodies on Bob & Larry and a smaller tip for the detailing.
The cakes were a huge hit. We used one of the cupcakes for my daughter to blow the candles out on (therefore keeping all the kid-spit off the real cake).