I am making a sheet cake for about 80-100 people. I have always made 1 9x13 white cake and 1 9x13 choc cake for a 1/2 sheet- Is this the correct thing to do? For a full sheet would I use 4 of the 9x13 cakes and piece together or should i just use the 15x20 sixze? Will this be enough for 80-100people. Thanks for help in advance.
"sheet" size seems to vary where you live. Two double-layer 9x13 would serve approx. 90. Here's a Wilton chart for party cakes - http://www.wilton.com/cake/cakeprep/baking/times/party_2inch.cfm
A 9x13x2" cake should serve 20 2x2x2" pieces.
Double that = 40 whether you make it 18x13x2 or 9x13x4.
To serve 80-100 you will need 4 or 5 9x13s no matter how you put them togetehr. If they are 4" tall then the 'slice' will be 1x2x4; if the cake is 2" tall the 'slice' is 2x2x2 -- each is the same amount of cake just cut differently.
BTW: I don't think I've ever heard of a 15x20 pan There are 11x15, 12x16 or 12x18 pans.
Hi and Welcome, Kimlee.
Here's the link to all four Wilton cake and serving charts so you can choose either the wedding size (1x2x4) or party size (1-1/2x2x4) yields:
(Includes both 2 and 3" deep pans.)
Have you considered using square pans:
12" would yield 96 party servings (layered cakes back to back).
16" would yield 80 party servings (single layers back to back).
Indydebi does sheet cake math:
(You decide on 2x2 or 2x3 slices.)
Previous threads on sheet cake size terms:
Found a 15x21x1 pan which is described as 3/4 sheet:
Using this size layer cake would yield 70 wedding 2x2 slices, or fifty party 2x3 slices.
(I have a 14x22 pan)