On Sun, 7 Mar 2004, N. wrote:

> These questions may seem like a no-brainer to some of you, but I'm not
> a baker by any stretch of the imagination so I need help!

I'm very much an amateur at this too. You need to take this with the
understanding that I'm working on trial and error most the time. 8^)

> I have a recipe for a cake that recommends using two 10x3" round pans
> and yields 9 cups of batter. How much of this cake batter would I
> need to fill a 11x15x2" rectangular pan? I guess I would fill it up
> 1/2 way and then bake until it's set in the center and hope for the
> best? Would the edges be overbaked by the time the center was set?
> Can I prevent this from happening? Is there any way possible that I
> can still follow the recipe as is and make 2 sheet cake layers out of
> it so I can use a filling (whipped cream type of filling) and still
> have it coming out tasty (not dry, crumbly, etc)?

I have recently started making cakes for large groups. I take recipes I
know work for 8" or 9" rounds and convert them to half sheets or large
pans like an 11x15".

My thinking, and this is were I'm guessing, is that the batter should be
the same depth. So if the batter in a 10" round is actually 1.5" deep then
I'd want it to be 1.5" deep in the 11x15". To keep the same depth I just
need to figure out the surface areas for the two pans and multiple as
necessary. So the area for a circle is PI*r*r. The math would then be:

two 10" rounds = 2 * 3.14159 * 5 * 5 = 157 units.

The surface area for the 11x15" is simply 11 * 15 or 165. I would guess
that you need 1.05 times the original recipe. You might be able to get
away with just using the original recipe.

Mind you, I seem to be lucky thus far. I've never read anywhere that this
works but it has for me so far. The problem you might have is that the
recipe calls for 3" high pans. Maybe the 2" high 11x15" is not high
enough. I've been in the habit of buying all my pans 3" high so I've never
had to worry about that.

Additionally, the recipes I use list instructions for converting to square
pans as well. Some recipes might not scale to square pans because the heat
from the sides is just as important as the heat from the bottom/top.

> Also, the key in the back of the cookbook says that a 10" round
> layered cake will yield 25 servings - does this sound about right? My
> daughter is having a birthday party and so I'll need at least 25
> servings for kids + adults.

If the recipe for the two 10" rounds will yield 25 servings then the
single 11x15" pan should serve just as much. Assuming the 10" round is two
layers, you'll want to cut the 11x15" in half and layer it. This will make
a 11x7.5" or 5.5x15" cake (I'd go the first route). I served 3x3" pieces
of two layer cake. People took it home. Couples shared one and took the
other piece home. There was a LOT of left over. Cutting the 11x7.5 into 25
pieces you are looking at approximately 2x1.5" piece of cake. That should
be plenty.

Mind you, if you are like me I'd double the recipe, make two 11x15" cakes
and create a 11x15" layer cake. I'd encourage people to take the extra
home and bring the rest to work for my staff. 8^)

--
Send e-mail to: darrell at cs dot toronto dot edu
Don't send e-mail to