I sure hope I don't annoy anybody with a repetitive question by asking but I have searched this forum high and low and my dilemma is a combo of different posts.  So maybe I am reading too much and getting confused.  I know that a 12x18 2 layer serves 100.

Here is my dilemma:

I'm baking these in jelly roll pans. 12x18

I need to feed 300

So I'm not so sure on the math for these cakes since they are nowhere near 2" deep.

I originally calculated that I would need 6 of these.  I planned on putting 2 12x18 side by side and stacking two more on top.  So I would have a double layer full sheet.

So that means a full sheet cake for presentation and then a half sheet 2 layer for cutting in the back.  Problem is I'm not sure if that is enough since I am using the jelly roll pan?  Does this make sense?

They are for a military ball and they want the logo on one of them. 

I will have the hubby make a plywood to carry these cakes.

I also realize that not everybody will eat cake. 

Any thoughts/advice/suggestions? Thanking you in advance.

first off, i hope you measured your pan because they come in so many different sizes these days--to get 100 servings you'll need three or four layers of cake--whatever it takes to get it 3.5" to 4" tall--then of course, three of those to get to 300--

if you just go with two layers and when finished it's about 2" tall then you'll have about 50 servings there so obviously you'll need 6 of those for 300--

plywood is so unforgivingly heavy--i would suggest using foam core board--the real thick stuff, i think it's about an inch thick or so-- or hot glue two of the skinny ones together--

best baking and caking to you

You can use bakeable cardboard trays inserted into your 12x18 jellyroll pans.

A[quote name="MBalaska" url="/t/773947/full-sheet-cakes-using-jellyroll-pan-for-300#post_7506855"] [B]bunkiesbakery:[/B] How did you get roped and tied into making cake for an army of people at a formal Military Ball, when you don't even have a big sheet cake pan?  What happened??

[I]suggestion:[/I] [B]beg, borrow, steal or buy a 12" x 18" x 2" sheet pan.[/B] [/quote

Yes, God! This is the question. You really need to get the sheet pans. The way you're describing it is going to be ridiculously stressful.

Using a 18 x 12 x 1 jelly roll pan for 300 servings.  Ouch!   You will need 3  4 inch high cakes to serve 300.  Since your jelly roll pan is only 1 inch high, you will need 4 layers for each cake.  3 x4 =12   So you will need to bake 12 18 x 12 x1 inch cakes. Good luck to you.

My husband is active army and I volunteered the cake. I know I know...a lot of you will disapprove but I just got an order for 200 cupcakes for it and I haven't even made the cake yet.  And the Battalion Commander didn't realize I baked and is now going to use me as his cake decorator.  Sometimes a headache is worth it!  It's the Houston Battalion so therefore a lot of exposure.  I am the only army spouse in the battalion that has a bakery. 

Okay, so I will get some cake pans those size then.  I do cookie decorating as well so I had a lot of those heavy aluminum cookie/jelly roll pans so I thought I would use those instead.  Figured it wouldn't take as long in the oven to bake as a 2 in deep cake pan but I see what you all are saying.

So, since I will now be baking them in half sheet CAKE pans, will 2 double layer full sheet cakes do the job?

A^^ Hey I'm in Houston too!! I don't actually think you SHOULDNT do the order. I just want you to get the pans lol...for your sake. Not sure about the serving count though

Woohoo! Hey fellow Houstonian!  But seriously I do see what y'all are saying.. I am DEFINITELY going to get those pans!  I rarely get asked to do sheet cakes so I only have 1 right now.  But if all pans out with the army, then it will probably be a good investment.  They are always having some kind of function, retirement, birthdays, promotions, etc.

Will also check into the foam core as well!

I have also heard about those boards that fit into those pans...that maybe a good idea as well!

http://cakecentral.com/g/a/59/military-police-fire-dept/

a little Inspiration from the gallery.  Lot's of sheet cakes here.

google 'sheet cake cutting  serving guide' for some help

Good choice to get 2 inch deep pans.   Here is the best cutting guide I have every used.  It works equally well for round, square and rectangular cakes.

http://cateritsimple.blogspot.com/2010/05/how-to-cut-wedding-cake.html

You might want to make camouflage cup cakes with swirl of army green frosting. 

a full sheet cake 1-layer serves 98 servings that are  2x2x1.5"  in size

so a 2-layer full sheet will serve 196 serving size of 1x2x4

so you'd need one 2-layer full sheet and one 2-layer half sheet--so they both yield 4" tall servings then you'd cut it all 1x2x4 and have a lovely boatload of beautiful cake--

if you're still doing the plywood (oh my aching arms ;) i'd plop the half sheet on top of the full sheet--stack 'em and dowel in there of course and be done with it--hoping you'll have some serious help to cart it all around--it will be outrageously heavy--but if it was me i'd simply do three two-layer half sheets for ease of handling--for all the stages of production and for ease of serving--

sounds like you have a good thing going--very cool--best baking to you

MBAlaska...thank you for that link! VERY helpful!

Narie, thank you for that cutting guide!

K8 - I have seen some pics of what you are saying, stacking the half on top of the full.  But you are right, aching arms indeed.  All of my help won't be available so I think I will go with your 2nd option and make 3 cakes.  One can have their logo and the other two can be plain and stay in the kitchen.  We are having it at a hotel so the kitchen staff will be available to help in that area.

Thank you all so much for your help!

so one more thought for you--no extra charge ;)

the thought of keeping a cake in a hotel kitchen makes me twitch intermittently when i'm not cringing--control is the name of the cake game--in this case 2/3 of your product is at the hands of others--who may put it on top of the stove/oven for a minute to get it out of the way--might put it in the walk in next to the cut onions or under the leaky rusty condensation in there or might put it on a work table free and clear where it might get bumped or be in the way...you get the idea--

me, i would decorate the two others in a triptych fashion--just use the same colors for the borders or slap some scrolls on there or whatever--

but i recommend keeping all your babies together and not abandon any of them--

all your call though--just a thought 

I never thought of that!  Well, I am a huge control freak.  I wonder since the main cake will be put on a table if I could request they keep the other 2 with the cake but withdraw them before the event? Knowing me, I will bring them all an hour early and change into my dress at the hotel.  I was cringing as I read your post!  I will gauge the event directors response when I contact him Friday evening...and also when I get there.

AI love making ball cakes, especially love watching the nervous guys getting ready to wheel a big tiered cake around the room. They always need reassurance, it's kinda funny. :D

AHahahah. Love it! Can't wait to see this in action!

So I wanted to come back and tell all of you thank you so very much for the much needed advice!  I couldn't find my 12x18 so I went with my 11x15 and ended up making 8 of those.  Made one full sheet cake and then made two separate ones for the kitchen to cut.

I thought it came out great!  There were definitely some things I need to work on. It was my first time doing drop strings and I thought I was going to die...I cursed a lot.  I marked them out but I guess I was concentrating too much and missed some of the marks because they are uneven.

But much to my surprise, the Lieutenant Colonel and Command Sgt. Major called me up to the front, gave me a certificate of appreciation and I got to cut the cake with them!!!! I was so happy!

holy moley--omgosh-- i completely teared up for you--wow wow wow

what a tremendous thing --wow

well add my multiplied congratulations to all those others too--

insert clapping hands smilie face here -- dang, girl -- cake's pretty too

sniff

wait--so are you on the right or the left in the photo--oh no --there you are--behind the little nose and teeth in the center--oh well--at least there's mostly great pictures of everything but you lol sucha momentous event --

i couldn't resist teasing you a little ♥

hang that certificate high and proud

AHahahahah yeah the hubby didn't get around to the front in time to get a better pic!!

Believe me I was pretty emotional! And thank you for the congrats and all of your help! I couldn't have done it without the amazing talent here on cake central! Cakemommy helped me a lot as well!

Congratulations Bunkiesbakery  that cake is awesome     "Army Strong"

AThank you MBAlaska!