Working for a colorectal surgeon there are so many dirty ideas that come to mind on his birthday. A butt cake would have been fun, but is such an obvious choice. I had seen a toilet cake somewhere in passing and knew I could come to this site for more inspiration.
I knew lemon cake was the perfect choice to go with the lemon jello/toilet water. I thought it would save me time just to use my angel food pan. So I baked my cake in that pan plus baked one layer in an 8 inch pan for the bottom of y bowl. Iced between the two layers with lemon curd, then cut out a larger circle in the middle of the angel cake. In the process I ended up sacrificing the connectivity of the back side of the toilet and had to use extra icing to piece it back together. I buttercream iced the entire cake except t he back side where the lid would be and the very bottom of the bowl. I speed set my jello and refrigerated it for 20 minutes. (I think 10-15 minutes would be the better choice to get a smoother top layer.) I then scooped the jelly consistency jello into the center of my "toilet bowl." Then placed the strategic brown fondant in the center. Letting it sit in the jello overnight created that loose stool effect in the morning. I shaped the seat bolts with white fondant and let it harden overnight.
I had to assemble the cake at work so I used my left over icing and "glued" the bolts and cardboard seat cover to the cake. Because of the on-site assembly I almost forgot to take pictures, so I was disappointed I didn't take more detailed pics. But it was still a hit! Disgusting yes, but awesomely funny!