1. Use unbounce app or something similar to design your landing page. I've seen too many clients spend piles of money on Twitter and Facebook ads only to watch it vanish with shitty landing pages.
2. Hire a professional to design your ads, manage campaigns and remarket (if using Facebook) using emails and website data.
3. Create value for them to want your product. Free giveaway, Ebooks download or study on baby food. Be human about how it benefits them. Be helpful, if your only trying to make money, people know.
4. Create a video campaign and blogs outlining the benefits of the food. The story, how it was made and why it's better than anything else.
5. Test it with local paediatricians. Let them in on the pre release and get their feedback. Use offline relationships to build online amplification.
Hope that helps. I'm sure others will have some other great thoughts too