We establish an experimentally accessible route to identifying Majorana surface states through their intrinsic Ising spin response, using UTe₂ as a concrete platform. The key is to extend the Majorana correlations into an adjacent metallic film via the superconducting proximity effect, thereby making the otherwise surface-localized response accessible to NMR measurements. Remarkably, disorder further sharpens the Majorana signature: impurity scattering suppresses the conventional p-wave proximity correlations while preserving the Majorana contribution, yielding a giant Ising-anisotropic enhancement of the NMR relaxation rate. This approach also offers a powerful means to distinguish among candidate pairing symmetries.