Very inadvisable. The stresses from laminating two boards and exposing them to extremes of heat and climate lead to great warping possibilities. The best old time thick doors were a poplar or white pine core with 1/8" hardwood veneer. In your case, you could resaw oak into 1/4" stock, laminate it to the core, then plane down to finished thickness. Unless your jambs are already determined, you could do a 2.25" door, which is a very substantial thickness.
The softwood core winds up much lighter than solid hardwood, which means it's easier on the hinges in the long run.
Casey