Method
Preheat oven to 325°F (165°C). Grease and flour a Bundt pan or two loaf pans.
Cream the butter, shortening, and cream cheese together on medium speed until very light and fluffy, 3–5 minutes.
Gradually add the sugar, beating until the mixture is pale and increased in volume.
Add the eggs one at a time, mixing on low just until incorporated after each addition.
Add the vanilla extract and (if using) salt.
Add the cake flour in three additions, mixing on low only until no dry spots remain. Do not overmix.
Scrape batter into the prepared pan and smooth the top.
Bake 75–90 minutes, or until a toothpick inserted comes out clean and the top is golden.
Cool in the pan for 15 minutes, then turn out onto a rack and cool completely before slicing.
Notes
Because there are no chemical leaveners, proper creaming is essential for lift.
Use ingredients at room temperature for best texture.
This cake freezes well when double-wrapped. 
