How do you actually bake a cake in an old Griswold cast iron cake mold?
The old two-sided cast iron cake mold belonged to my grandmother and is shaped like a bunny rabbit. One side has two vent holes, the other side does not. The pieces fit nicely together but easily come apart when trying to fill the mold with cake batter. I am at a loss. The box the mold came in is dated 1929 and the mold is made by Griswold, Erie, Pa.
Ok, it’s not as much rocket science as it looks, baffling as it does seem at first… 
Butter and flour your mould or, beter still, use a prof. baker’s release spray, treating both halves.
Put your mould half that has no holes — generally the ‘front’ or in your case the bunny’s face side — face down on a baking sheet. Fill this part of the mould generously flush. Settle the mixture well to prevent air pockets that will leave holes in the finish of the eventual moulding. Now place the other half of the mould (the one with the holes in it) on top.
(In case you’ve wondered, the holes are there to let the air out of the mould when the mixture rises, enabling the second half of the mould to be filled completely.)
Now it’s a case of baking according to the temperatures set for your mixture and, with maybe 20% of the time remaining, you can optionally choose to invert the mould to fix the shape of the half that has only been moulded by the upward surge of the rise until then.
When done, cool in the mould (shut) for a short while to let things set further, then carefully prise off the first half, relying on the cake release to do its business. Don’t rush this or you could find the moulding being damaged through minor ’sticks’ as you release it. When firming up nicely, repeat the exercise for the other half, and your ‘beastie’ should be complete.
Hope this helps.
Ps. OK, I have to fess up: I’m quite green with envy. )
My Day in Erie