Watching Ace of Cakes, it looks like they stack their cakes without trimming and leveling the tops or anything! Me, not only do I have to level off the tops every time, but usually even have to trim away the outer surface - top and sides - because it just seems harder/tougher than it should be. (baking from scratch)

What's the secret?? What am I doing wrong??

Do you get the bunp in the middle? They must do it buy measureing. I all most did it yesterday, only had to cut a little bit off of the top. I do use the box and add other things, but I bake at 325 not 350.

Forgot to mention, if you do get the bump or hill in the middle if you lower the temp. it will bake flat. It just takes longer to bake.

Try the strips along the sides of the pan. I also drop my pan to pop bubbles and even out the batter.

I never have to do any leveling on my cakes. No domes or anything else that needs to be trimmed.

I use Magic Line pans, no baking strips or flower nails or anything else. I bake my cakes at 350.

Putting too much batter in your pan can create more of a dome. Find what amounts work best for your cake recipes. I find that 1/2 full works best with my doctored recipes.
You can also bake at 325 for a little longer, and do not grease your pans, so that the batter can "climb" up the sides. I do not grease or flour my pans, I simply line the bottom with parchment paper and cool in the pan. Run a knife around the edge of the cake to release, and pull off the paper.
Baking strips help with larger cakes.
Commercial bakeries usually have convection ovens. These bake more quickly and evenly.

I grease-only my pans, baking strips, 325 degrees, minimal trimming.

The science of baking:

WHen baking, the heat source is at the bottom of a standard oven. The heat is pushing the batter up the sides of the pan. When the pan is greased, the batter climbs more easily ..... "slides right up" the greased sides, and climbs higher. When the pan is not greased, the batter "grabs" onto the sides of the pan rather than sliding right up the sides of the pan. My cakes usually rise higher than the pan.

after the cake cools for about 5 min, put on your mitts and push down lightly on the center of the cake and smooth it that way, it will get as flat as you want it

A friend of mine who decorates cakes and has her own shop told me to shake the pan to make the dome fall when it is baking.

Wow, what great advice. I will try them all!

What about the outside edges of the cake? Do you need to trim it all off, or is it ok to have a tanned outside layer on your cake (under the icing)?

no you do need to trim it. those edges are usually perfect from the pan and trimming may cause it not to be so perfect, plus you would have many more crumbs to deal with.

where can you find the "magic line" cake pans that were talked about?

I need some magic line pans!!!

I read that one way to make sure that the cakes don't get the dome on top is to gradually adjust the baking temperature at various intervals...

Start out baking the cake at 300 degrees for 15 minutes, increase the temp to 325 degrees and bake for 15 minutes, then increase to 350 and bake for an additional 15 minutes. I've tried it before -but can't remember what results I got

I'm sorry, I meant to type you don't need to trim the edges...that's what I get for not proofreading!!!