A question about a recipe: Not Red Velvet Cake with Fudge Glaze

Another question made me think of this one also. You might want to consider using cake flour--it has a lower protein content and won't develop as much gluten, so your cake will be tender.

That's a good list -- thanks!
I'll try it again -- it wasn't bad the first time, just not quite what I'd hoped.

All of the above information is spot-on. I'd add that sifting the dry ingredients is pretty critical. And when you add the eggs to the butter-sugar mixture, first crack them all into a measuring cup (it has a good pouring spout), and add them one at a time, allowing each to be fully incorporated before adding the next. Stop the mixer and scrape the bowl thoroughly before adding the dry ingredients. Add them in thirds, alternating with the buttermilk. After each addition, let the batter mix just long enough to hydrate the dry stuff. Scrape the bowl completely after all have been added, then mix briefly one last time. Even with cake flour, it's perfectly possible to overmix your batter, which overdevelops the gluten and results in a tough cake. Persevere!

Whoops, make that beating the butter and sugar in step 3.

I made this cake 2 weeks ago and it was not at all dense, just the opposite, very much like a store-bought mix with better flavor as A&M said. In addition to the other answers, I would suggest you make sure you are beating the cream and sugar enough in step 3 to get them light and fluffy---I usually do 3 to 5 minutes on speed 4 of my KitchenAid. That will make sure the cake is well aerated.

I agree with hla--definitely check your oven temperature and your technique for measuring flour. Liquids, too--get at eye level with your measuring cup (and use a measuring cup that's meant for liquids) to make sure you're measuring accurately.

Have you checked your oven temperature? If not, purchase an oven thermometer and check it.
How do you measure your flour? If you're not using a scale your measurements may be inaccurate. I'm a big fan of the scale for baking especially. If you don't have a scale check out Merrill's demo for measuring flour. Definitely sift or whisk the flour before measuring -- 1 cup sifted flour has less flour in it by weight, than 1 cup non-sifted flour. http://www.food52.com/blog/2227_how_to_measure_flour