I have been looking for this recipe since my mom died. It is the only recipe that calls for confectioners' sugar in the cake mix itself. It is the very best white cake recipe. The first time I remember watching her was about 60 years ago. I asked her why we were making the frosting before the cake when I saw her put the confectioners sugar in the bowl along with the shortening. We used a cooked flour frosting that called for flour and milk cooked together into a thick paste and added to 1 cup shortening and 1 cup granulated sugar that had been beaten with a stand mixer for at least 15 minutes with the paste mixture added by teaspoons while still warm. It is the best white cake recipe!