Cole W. Minnick, president and CEO of California Oaks State Bank, has resigned effective April 15. Minnick, who joined the Thousand Oaks-based bank in 2003, did not reveal his immediate plans. Bank officials said the current management team will lead California Oaks through the succession while they launch a search for a successor. Minnick joined the bank following an accounting scandal involving its former CFO and oversaw the institution’s turnaround.