Is there a chart somewhere that shows how many cups of batter are needed for various size cake pans?
I am making a cake for my niece. It needs to serve 15, but I know how my family cuts cake and they will cut large slices and many will want seconds or leftovers for later. I am positive a 2 layer 9 inch round would be too small. I was thinking of doing a 1/4 sheet 2 layer or possibly a 10 inch or 12 inch round. I don't have a good concept for how large those are relative to each other though.
This is the chart I use all the time.
A single layer 13x9 serves about 25 2x2x2in slices. A double layer would be 50 1x2x4in slices.
According to this chart a two layer 9in round serves 32 1x2x4 in slices. Which is double what you need, but would accommodate slicing them larger.