Unfortunately, it looks like there was a bit too much air in the batter, as it had already escaped from the mold, flowed over the edge of the cookie sheet, and was burning on the bottom of the stove. Then when I went to turn the mold over, the mold separated and more batter flowed out onto the cookie sheet.
The lamb cake is now done, but not very much like lamb cake. Gretchen says she'll try again tomorrow.
The overflow tastes good though. (The part on the cookie sheet. The burned part on the bottom of the stove I've now thrown away.)