Grease and flour a 9-1/2″ to 10″ tube pan. Set aside. Heat oven to 325°F.
In a large bowl, sift together flour, 1 c. sugar, baking powder, salt, and cinnamon. Make a well in the center and pour in oil, egg yolks, water, and vanilla. Beat mixture until smooth (3 minutes minimum). Set aside.
In a large, clean bowl, whisk the egg whites and cream of tartar until the cream of tartar is dissolved and egg whites are foamy. Gradually add remaining 1/2 c. sugar and beat mixture until soft peaks form.
With a large rubber spatula, stir about one-third of the egg whites into the yolk mixture. Gently fold in the remaining egg whites until no white streaks remain.
Pour batter evenly into tube pan. Bake approximately 1 hour or until cake springs back to the touch and a clean toothpick can be removed from the cake when poked.
Invert the pan onto a bottle with a narrow neck and cool thoroughly. Remove cake from the pan and slide onto a serving plate. Sprinkle with powdered sugar and cinnamon mixture. Serve and enjoy!