I have a really good banana cake recipe using a mix. It turns out great when I follow the recipe, but when I try to double it for a larger pan it always falls in the center and seems so greasy. Any ideas on how I should adjust the recipe to double it?

Banana Cake
2 T lemon juice
2/3 C milk
2 large very ripe bananas
1 package yellow cake mix
1 tsp baking soda
1/2 C butter
3 eggs
1tsp vanilla

Of course I need it for saturday and I have ruined 1 already!
Thanks!

Are you using a heating core or a flower nail in the center? If not, thats probably the reason. If so, I don't know. If you have a flower nail, spray it with pam (or whatever spray you use) and put it into the center of the pan upside down before filling it with batter. Leave it in to bake, and when you take the cake out, it will pull right out of the center. I use one for any cake 10 inches or over. Good Luck!

Thank you!
I will try the flower nail
It's a 12 inch cake I'm trying

I had this exact problem yesterday with a 14-inch white chocolate cake. I never had trouble with the recipe before but I had never made such a large cake before either. I ended up going to Michael's and buying the $6.00 heating core. It worked like a charm! I tried the flower nails on the first cake but I think the job was too big. Maybe a 12-inch will work though. Good luck!

Bananas have a lot of fat in them. Is the butter necessary? Maybe use butter extract instead?