Existing GFCI outlet wiring to a new switch
While it's possible that the receptacle is split and fed by two sources, it looks like the tab between the terminals is still in place.  This means that one of the cables is likely the supply (from the panel), while the other feeds devices further along the circuit.  

If the tabs between the terminals are in place, then it's not fed by two sources.  You can connect the blacks to blacks, the whites to whites, and the grounds to grounds.   

From there, I'd suggest installing a combination switch/receptacle. Running a cable up to where you want the new receptacle, and hooking up the new receptacle so it is controlled by the switch. 

That way you don't completely lose the existing receptacle, but you still get your switch controlled lighting.

Depending on the device used, the wiring would look something like this.



NOTES:  


Since this is a countertop receptacle, it has to be GFCI protected.  If it's not already protected, you'll have to install a combination switch/GFCI receptacle.  In which case, the wiring will be slightly different.