I read somewhere to put 1TBLS of meringue powder in your cake batter but I cant remember why it said to do it. Anybody know?

It is suppose to help make it rise higher. Adding an extra egg white would do the same thing.

I use to add MP to my cake mixes, but never really tested it side by side with a cake I didn't use it in to see if it actually made a difference. I haven't added it in years though.