Hello everyone!

I have a simple question. I am looking to start a handful of new food-related content sites for some long-term organic income, but I have a question regarding the domain names. Now, I can buy a simple exact match domain name [keywordhere.com] for each site... or could I do this:

keyword1.com and create a simple content site there.

Then, I could do:
keywordthree.keyword1.com, etc.

Would there be a difference in ranking if I just made a whole domain name for each keyword, or if I used the keywords in subdomains?

Example for Clarification:

Would cakekeyword.cookingtips.com rank as highly for cakekeyword as if I just did cakekeyword.com?

Edit: Alternate Idea
Maybe it would be best if I just did keyword1.com/cakekeyword.html or something?

Please help!