If you have $300k in cash to invest, what would you do?

If you had $300k in cash savings that is currently parked in a high yield savings account, how would you invest it? We already have a decent amount in retirement savings and looking to maximize what that can do for us. We're in our mid 40's and currently on track to be able to retire by 55. Any advice is much appreciated.

I'm posting this a little late on Saturday night, So I'll be able to respond to any questions/comments tomorrow.