A gas turbine engine component according to an exemplary aspect of the present disclosure includes, among other things, at least one cooling passage. The at least one cooling passage includes a first wall and a second wall bounding the at least one cooling passage, the first wall having a plurality of first surface features and the second wall having a plurality of second surface features. The plurality of first surface features and the plurality of second surface features are arranged such that a width of the cooling passage varies along a length of the cooling passage defined by the plurality of first surface features and the plurality of second surface features. The plurality of first surface features has a first profile, and the plurality of second surface features has a second, different profile. A casting core for forming cooling passages in an aircraft component is also disclosed.