A vane arc segment includes an airfoil section, a spar, and a baffle. The spar supports the airfoil section and has a leg that extends in an internal cavity of the airfoil section. The leg is spaced from the airfoil wall such that there is a gap there between. The baffle divides the gap into a plenum space between the leg and the baffle and an impingement space between the baffle and the airfoil wall. The baffle has impingement holes directed toward the airfoil wall that connect the plenum space and the impingement space. The impingement space is of substantially uniform thickness and the plenum space is of non-uniform thickness along a portion of the span length of the airfoil section.