I have tried twice to make a scratch chocolate cake, using the Hershey's Perfectly Chocolate recipe and the Hershey's Black Magic recipe. Both times they fell, drastically. Sadly I can whip up a scratch chocolate cake by mixing everything with a fork in a 9x13 pan and it turns out every time. I've seen a few suggested modifications, like substituting sour cream for the milk and reducing the leaveners. I think I also read that someone doubles the flour. I live at 4300 feet, could it be simply a matter of adjusting the recipe for high altitude? (which I have not tried). Since I need a family birthday cake tomorrow I will resort to the brute 9x13 stir-in-the-pan method and offer apologies.

No idea on the high altitude sorry. I use the Hershey's recipe but I add an extra 50% of the flour amount called for when I make it.

If not too late try this.  I have made it 100 times with not one problem.   It is very easy to make and has a  very rich dark chocolate flavor but not dense,  I use Hershey's special dark cocoa and full fat bulgarian buttermilk.  Leave out the almond extract if you don't like it, but I love the flavor it adds.  Can't vouch for the frosting.  Good luck!

http://www.pillsburybaking.com/recipes/deluxe-devils-food-cake-3107

 For Yortma's recipe:

High Altitude (above 3500 feet):

• HEAT oven to 375°F. Decrease sugar in cake to 1 3/4 cups and baking soda to 1 1/2 teaspoons. Increase cake flour to 2-3/4 cups. 

Thank everyone for your replies.  I lost sleep over this one.  I will do some studying before my next chocolate cake attempt.  

My advanced cooking class students just finished a chapter on baking and we had cupcake baking day in which some of them failed miserably! (in a funny way!).  Too much leavening causes a cake to fall.  The extra leavening creates larger carbon dioxide bubbles, which get too large, and they can't sustain their size, so they burst, causing the baked item to fall.  LEavening is the baking powder or baking soda and can also be mechanical leavening (such as whisking or whipping).  Overmixing, which is a mechanical leavening, can cause a cake to fall.

You should have seen the cupcakes in which they used the whip attachment (adding extra leavening) AND they measuring out something like 1/2 cup of baking powder instead of 1/2 tsp!!  (and these are the ADVANCED class kids! LOL!)  It was like a lava explosion in their ovens!  But it was also the best lesson I could have ever NOT planned to show them how leavening and carbon dioxide bubbles work!

Gotta love those lessons learned the hard way.  I always use my KA beater blade and mix no longer than 2 minutes on medium speed once the flour and eggs have been combined.  I am currently studying cake ingredient ratios and will analyze the recipe I used to see how it stacks up.  One thing I have not yet found a rule for is the leavening (which I understand will be slightly less at my altitude).