not rise in the middle? I mixed up the correct way, put it in a 10" round pan with a flower nail in the middle, stuck it in my 325 oven which had preheated for 30 minutes and only the sides rose. I'm lost... I try a boxed mix (my daughter wanted confetti for her birthday) and it flops! Who woulda thought scratch is easier?
Well for starters are you *sure* your oven temp is correct?
How long did you bake it? Usually for me (at 325 degrees) it takes about 20-30 minutes for that size.
What is the elevation where you live?
maybe the mix was just bad or old? I would check the box and see if there is a expiration date maybe it just went bad... for sure not your fault!!!! Try again.. and Happy Birthday to your kiddo... sprinkles rock