Financial Gift From Parents for Grand(Kids)

Hello,

I am a PGY-1 and first time parent to a child as of one week ago. I have my fair share of student loans and have been balancing aggressively paying them off as well as maxing my roth 401k match and my roth IRA. Recently, my parents stepped in and offered to superfund an investment account for my 1 week old child to pay for future college expenses. I am so grateful they have offered to do this because this was not on my radar. What account should I ask them to put this money in that would be most advantageous for my family?