I'm not sure what I'm doing wrong. All cakes I bake have peaks. I've tried baking lower and higher in the oven but it doesn't really help.

I know you can cut the top off and flip over, but when doing cupcakes I'm a bit stuck.

Any ideas?

What kind of pans are you using? If they're not heavy duty professional ones like Magic Line, it might be the culprit. The solution is to buy cake strips to surround your pan from your local bakery supply. Some people make their own by wrapping folded up wet paper towel with aluminum foil and clipping it together.
It's all about science, and cheaper pans get hotter faster, cooking the outside before the inside is done, this forces the batter to rise in the center. Obviously, this probably would be a hassle with a cupcake pan, so my only suggestion is a better cupcake pan maybe? Hope I helped a little, anyway. lol.

I am no expert but after browsing this site I found someone who was having the same problem. They used a 7 inch metal flower nail in the centre on their cake (base flat and pointing upwards) which was placed in the pan before pouring cake mix on top. Apparently it acts as a second heat source for the cake allowing the mixture to cook evenly in the centre (as the sides cook first and middle last) which made the cake almost flat on top. I have not had the chance to try this yet as only found it last night but they swear by it. And I will be trying it x

One method I have used is to get a few strips off an old bath towel cut to the width of my cake pans. You wet them, wring them out so as just damp and wrap them around your pans just before putting cake in the oven, works quite well.

Also if your cake comes out with a dome in the middle, as soon as you take the cake out of the oven - using a clean tea towel, lay the tea towel over the top of the cake a press down firmly to flatten the dome, the cake is still very hot at this point so be carefull not to burn yourself.
Just a few ideas, hope they help.