dialogue - What would Jacob Palmer's (Ryan Gosling's) accent in Crazy Stupid Love be classified as?

That's called phony accent.

Ryan Gosling told to W magazine about his infamously slurry speech,

"As a kid I decided that a Canadian accent doesn't sound tough. I
thought guys should sound like Marlon Brando. So now I have a phony
accent that I can't shake, so it's not phony anymore. I'm going for
the Madonna thing, the Lady Gaga thing--a phony accent that becomes
your trademark."