Thanks for the tips about making cake dense and easier to carve! So as not to have tons of cake, my first attempt at a tiered cake included one solid 8" round yellow cake base, two 8" chocolate rings, two 5" round middles cut out of the chocolate cakes to become the second tier, and a third little tier from a cupcake. Working with frozen cakes for carving and putting the cake in the fridge after the crumb coat really helps. I used DH Classic Butter Golden Deliciously Moist Cake Mix, one additional egg (4 total), 1/2 cup additional vegetable oil (it plus 7 Tbsp soft butter total), 2 Tbsp less of the 3/4 cup water, plus one 3 oz box Jello vanilla Cook & Serve pudding & pie filling (uncooked pudding filling, just dump from box on top of cake mix). I used BC Delights Super Moist Triple Chocolate Fudge Cake Mix, one additional egg (4 total),1/2 cup additional vegetable oil (1 cup total), 2 Tbsp less of the 1 1/4 cup water, plus one 3.4 oz box Jello chocolate Cook & Serve pudding & pie filling (uncooked pudding filling, just dump from box on top of cake mix). Banging the cake pans several times (maybe 100 times each) on the counter to bring up and "burp" all/most of the bubbles helped. Baking at 300 until a toothpick came out clean or with crumbs - not wet - made for a flat dense cake. I did not have to level at all. I froze them before cutting. Also, they were delicious, especially the chocolate cake. THANKS!

1/2 cup additional vegetable oil (it plus 7 Tbsp soft butter total),
Read more at http://www.cakecentral.com/forum/t/659288/how-do-i-doctor-box-mix-to-make-more-dense#OdLCKtKB1zKG8SBu.99

Thank you! I didn't have to level at all. Thanks for the tip!

Why not try a real scratch cake like a madeira? Dense, moist delicious and easy, plus you can speak with confidence about the purity of your ingredients.