Powdered or extra-fine sugar, for dusting
Heat oven to 350 degrees. Butter and flour two 9-inch cake pans. Sift flour three times and add baking powder and salt. Set aside.
With electric mixer, cream butter and sugar until light and creamy, about 10 minutes. Add eggs one at a time, beating well between additions. Add vanilla and orange bitters.
Divide flour mixture into four portions. Set electric mixer on medium low and add flour alternately with orange juice, starting and ending with flour. Mix just until incorporated after each addition.
Divide batter evenly between cake pans and bake 35-40 minutes, or until cake pulls away from sides of pans. Remove from oven and cool 5 minutes in cake pans before turning out.