Need camera advice for my specific needs

I'm creating a website for my uncle's bakery and I'm in the process of creating a gallery page where I'll be uploading every cake he makes to add to his portfolio. I told him to send any pictures he has and as you could see by the images in the link, they're really low quality and unprofessional. I'm pretty sure they were taken with an old smartphone, and he didn't even bother to make sure it was in focus. I'll be the one taking the pictures from now on so I'll just educate myself if I'm not familiar with your recommendations. The quality I want to achieve is that of the cakes you get on google images. What would you guys recommend? My iPhone 7+ camera, iPhone lens attachment, DSLR? Willing to spend up to $500, however, I would prefer not having to spend that much. If a $300 DSLR camera could do the job, so be it.

Old Photos





What I want to achieve:


Added (1). Thanks in advance!

Read more: Need camera advice for my specific needs