The cable you're looking for is called a direct connect cable. "Fake" optical modules on both sides, plugs it together with a permanently wired copper cable.
DAC is a common term for this. Direct Attached Copper.
It is a SFP+ plug on each end (but without all the optical magic), connected with twin-ax cable, which is like coax but with 2 signal paths, one for each direction.
It is a SFP+ plug on each end (but without all the optical magic), connected with twin-ax cable, which is like coax but with 2 signal paths, one for each direction.