In this paper, we construct a differential graded Batalin-Vilkovisky (dgBV) algebra P V * , * (X) associated to a possibly degenerate Calabi-Yau variety X equipped with local deformation data. This gives a singular version of the (extended) Kodaira-Spencer dgLa in the Calabi-Yau setting. We work out an abstract algebraic framework and use a local-to-global Čech-de Rhamtype gluing construction. Under the Hodge-to-de Rham degeneracy assumption as well as a local assumption that guarantees freeness of the Hodge bundle and applying standard techniques in BV algebras [35,32,51], we prove an unobstructedness theorem, which can be regarded as a singular version of the famous Bogomolov-Tian-Todorov theorem [3,52, 53], in the spirit of the work of 32]. In particular, we recover the existence of smoothing for both log smooth Calabi-Yau varieties (studied by Friedman [16] and ) and maximally degenerate Calabi-Yau varieties (studied by and ). We also demonstrate how our construction can be applied to produce a logarithmic Frobenius manifold structure on a formal neighborhood of the extended moduli space using the technique of 1].