I am making a 2 layer 10 inch round cake for a bridal shower this week. There will be 15 people there, will that size feed them or should I make a 12 inch round?
That's plenty of cake for 15 people. I just made one yesterday and had half the cake left over and there were 12 people there, and I cut the pieces huge.
When cut in the industry standard serving of 1x2x4, a 10" 2-layer round will serve 35-38 .... so you will have PLENTY of cake!