I have this red velvet recipe that came from a very old cookbook, it is wonderful. However it domes up really nicely for cupcakes in the oven, and then deflates to a flat top. Can anyone help me figure out a way to possibly make it hold that pretty dome? I do not know how to alter recipes other than small tweaks here and there and could use some advice. Any help is much appreciated! Thanks!

Sift your baking soda with the flour. Mix the vinegar with the milk.

The dome comes from that initial "push". When you mix the ingredients another way, you get less of a dome but it won't fall either.