Place Abuelita chocolate, 1 can evaporated milk and unflavored gelatin mixture in a blender; cover. Blend until smooth. Pour mixture into a baking dish; refrigerate until slightly set. Cut into squares; pour squares into a lightly greased gelatin mold and refrigerate.
Place water and evaporated milk in medium saucepan; heat over medium heat. Add eggnog-flavored gelatin; mix until completely dissolved. Cool to room temperature. Pour over chocolate gelatin cubes and refrigerate until set.