In large bowl, beat 1 cup softened butter and the granulated sugar with electric mixer on medium speed 2 minutes, scraping bowl occasionally, until fluffy. Beat in eggs, one at a time, just until smooth. Beat in 2 teaspoons vanilla. On low speed, beat in one-third of the flour mixture, then half of the milk, beating well after each addition, just until smooth. Repeat with flour mixture and milk, ending with flour mixture, scraping side of bowl occasionally. Spread 4 cups vanilla batter evenly in pan.