The senior knocked down six three pointers before halftime and finished with a team-high 19 points as Lafayette handled Grandview 70-43 on Saturday to earn a Class 4 state berth for the second time in four years.
It's the second trip to state for the Irish under head coach Chris Neff.
Five of Cook's threes came in the first quarter, capped by a buzzer-beating shot from just in front of the half court line. Already up 18 in the second quarter, Lafayette continued to hit from beyond the arc. Gary Wilkinson launched his own shot from the wing as the halftime horn sounded, giving them a 37-14 lead.
The Irish were on cruise control in the second half as Wilkinson finished with 12 points. Xavier Kurth and Chester Goudeau each added 15.
Lafayette will face Farmington in the Class 4 semifinals at Mizzou Arena on Friday at 6:00 p.m.