I have a couple of questions. I was wanting to fill the pan 2/3, was going to use the WASC recipe, well the chocolate version, so I'm assuming I'll have left over batter? Or does it take the whole recipe?

I was also wondering if it takes a long time to bake? I usually bake at 325, 8 inch rounds with 3 1/2 C batter in each, for 55min. I'm assuming this cake will take longer to bake? Should I use a few flower nails in the centre to help? I'm worried about it sinking in the middle.

Any advice and/or tips would be greatly appreciated! Thank you.

I bake that size ALL the time , but I use two cakes mixes. Bake at 325 for between 35-50 min depends on the day.

I meant to add I do not use a flower nail.

The chart I use (I think it's from Wilton) says an 11 X 15 pan takes 2 cake mixes. I would think if you made the WASC recipe with one cake mix even with the additional flour and sugar you still would not have enough for the pan. If you use the recipe that uses two mixes, then yes you should have some left over.

When I make an 11 X 15 I use two cake nails, one at either end. I also use baking strips and set my oven to 300 for the first half of the baking time and raise to 325 for the second half.

HTH.

Thank you guys!