Everytime I make a chocolate cake (box mix) in my 12X12X3 pan it takes soooo long to bake and it comes out dry!

Any tips or suggestions???

I'd recommend using any of the chocolate variations of the WASC cake recipe as it always comes out moist.

Here's a thread on stacked/tiered/layer cakes that has both versions of the WASC cake recipe (with and without oil/fat) and chocolate variations:

http://cakecentral.com/cake-decorating-ftopict-605188-.html

Another chocolate variation by Cakepro:

http://cakecentral.com/recipes/7367/amazing-chocolate-wasc-cake

The above thread also has links to Wilton's cake preparation and servings guide which gives batter requirements by pan size and recommended baking temps. and times.

A 12x12x3 pan takes 14 cups of batter (per layer) - so a full recipe of the WASC should work out perfectly for you. I'd also use either inverted flower nails or a baking core and bake-even strips to help the center bake while preventing the edges from becoming over done (both discussed in the above thread).

Good luck!

HTH

P.S. Investing in a separate oven thermometer to make sure your oven is baking at the right temp. is also a worthwhile investment.

I would agree with JanH. If you use a WASC chocolate cake recipe you will have better luck. Just in case you don't already know, that is a doctored box mix recipe where you add to the box mix. Also, the bake even strips can just be a cut towel that is damp with water and hooked to the outside of the pan. (Can be with a binder clip)