The stellar progenitor problem for Type Ia supernovae is widely recognized as one of the key questions in modern astrophysics. Perhaps the leading theoretical challenge shared by all SNe Ia channels is the detonation initiation mechanism within the dense electron degenerate plasma in the white dwarf interior. The turbulence-driven deflagration-to-detonation transition (tDDT) mechanism is a recent laboratory-validated advance towards a first-principles understanding of this central challenge. I will present new global 3D full-star hydrodynamical simulations of near-Chandrasekhar mass (near-Mch) SNe Ia, with a detailed analysis of their turbulently-driven burning fronts. I will discuss the onset of a tDDT within these new 3D models. I will conclude with the implications for the observable nucleosynthetic and spectral signatures of a tDDT-initiated near-Mch SNe Ia event, relevant to both optical observations of SNe Ia transients as well as X-ray observations of SN Ia remnants.