ADon't want it to be burnt on outside and mush in the middle. It's my first one, thankfully not for a real client.. Well she is real lol! But a family member. One week from today. When should I start baking do you think?! And what temperature and for how long. Freaking out. I am using a big oven proof bowl. The average size of other belly cakes

That is going to be one HUGE belly :)

Bake it the same as any other cake - temp at 325 but probably for a longer time.  Since we don't know  exactly how big you big bowl is (how may cake mixes does it hold?) I cannot even begin to suggest a time frame.

AIt's gonna be the same size as every pregnant belly cake I've seen lol. I thought someone would know what temperature. I figured it out on my own after waiting hours with no replies! I just wanted a quick answer. No one ever really helps me on this site lol I never would've guessed cause I bake all my cakes at 350. But at 315 for about and hour and 15 mins worked. No hard crust or anything! Woo. That was a test cake hope the real one goes just as good lol!

In the future when making a belly cake in a large bowl, as I have done many times, it is best to put a heating core in the bottom on the bowel, such as a large flower nail. This will insure your cake is always baked evenly. Hope your cake turned out nice :)

I would make a belly cake with stacked round cakes.  You can choose the the diameter you want, and stack graduated sizes to get the general shape (ie:  2 10", a 9" and 8" and 6"etc for a BIG belly!).  The stack is then  carved to a rounded shape.  I like this way because you have filling rather than just cake, and the baking is not problematic because it is made of regular rounds.  You can bake as far ahead as you like.  I virtually always freeze my cakes until the day before. When ready, take them out of the freezer, stack them up and carve before  fully defrosted with a good sharp knife to the shape you like.  You can use the bowl as a guide. It is easier when they are partly frozen.  Then put filling between the layers and do a little touch up shaping and carving before crumb coating.  HTH