[quote author=“Julie” date=“1361561210"Two 8x2 rounds would have a capacity of about 14 cups. If your 11x15 pan is 1” deep, it would have a capacity of about 11.4 cups. Pans should be filled half to 2/3 full, so if the recipe fills the 8x2 pans half full, you will probably have about the right amount of batter. If the recipe fills the 8x2 pans 2/3 full, you will have too much.
A 2” deep 11x15 pan has a capacity that is about 22.8 cups, so you would need to multiply the recipe by 1.63 or about 1 2/3.
If this is a butter cake, pans should be filled half to 2/3 full of batter or they may not bake up properly, it doesn’t always work to just fill the pan less than half full in order to avoid torting the cake.
All that said, if your 11x15 pan is a cookie sheet with sides 1/2- 3/4” deep, then it won’t require as much structure as a deeper pan, so you may be fine without adjusting the leavening. Perhaps a cookie sheet is the way to go, in order to get both thinner layers and to have less need of adjusting the leavening.
The pan I’m using is a 3” 11x15 however I’m not looking for a 3” high cake. I really don’t want it any higher than 2” as I’m carving a violin from it.
According to the charts on line, an 8x2 pan requires 3-1/2 cups of batter so given that I would estimate that the recipe yields 7-8 cups of batter, possible a bit more.
According to the same chart, an 11x15x2 requires 11 cups of batter. I did measure out 14 cups of water into my pan and it filled the pan to a 1” depth. So I’m not sure how accurate the chart is.
When you refer to the capacity of the pan, are you talking about total volume if one filled it with water to the top?
The recipe I’m using is:
2c cake flour
1 tsp baking soda
1/4 tsp salt
1 tsp vanilla
I was thinking of just doubling the recipe hoping that would give me the volume I needed.
In terms of the leavening, does it need to be adjusted to compensate for the larger area of the 11x15 pan?