What's your play KK vs min-raise post flop

[Acein8ter]

No reads. I PFR 3xbb and get one caller. Pretty safe flop and I want to extract as many chips from villain as possible. (I'm pretty sure I'm ahead) I bet ~1/2 and get min-raised. What's your play here?

Full Tilt Poker, NL Hold'em, 1,000/2,000 Blinds, 250 Ante, 6 Players
LegoPoker Hand History Converter

BTN: 26,750
SB: 20,290
BB: 54,553
Hero (UTG): 47,908
MP: 26,047
CO: 94,452

Pre-Flop: (4,500) K[img]/images/graemlins/diamond.gif[/img] K[img]/images/graemlins/club.gif[/img] dealt to Hero (UTG)
<font color="red">Hero raises to 6,000</font>, MP folds, CO calls 6,000, 3 folds

Flop: (16,500) 8[img]/images/graemlins/heart.gif[/img] 3[img]/images/graemlins/spade.gif[/img] 8[img]/images/graemlins/club.gif[/img] (2 Players)
<font color="red">Hero bets 8,000</font>, <font color="red">CO raises to 16,000</font>, Hero ?