Butter and flour (I like to use non-stick cooking spray with flour) two 6-cup Bundt pans.
In large mixing bowl, beat butter and cream cheese on medium speed until fluffy, about 4 minutes. Add sugar and salt; beat 10 minutes, occasionally scraping down sides of bowl. Add eggs 1 at a time, beating until blended after each addition. Beat in vanilla. Beat in flour at low speed until batter is smooth (do not overbeat). Divide batter evenly between two pans.
Place pans in cold oven. Set temperature at 200°F; bake 20 minutes. Increase temperature to 250°F; bake 20 minutes. Increase to 275°F; bake 10 minutes. Increase to 300°F; bake cake and additional 10 - 15 minutes until tester inserted near center comes out clean.
Cool cake in pan on rack 10 minutes. Turn cake out onto rack; cool completely. (Can be made 3 days ahead. Wrap; store at room temperature.)
Notes
*I used 2 ¾ cups sugar to adjust for my altitude. Slightly adapted from Epicurious