In large bowl, beat 3/4 cup butter and the granulated sugar with electric mixer on medium speed, scraping bowl occasionally, about 2 minutes or until fluffy. Beat in eggs, one at a time, just until smooth. Stir in 2 teaspoons vanilla. On low speed, beat flour mixture into sugar mixture alternately with 3/4 cup milk, beating after each addition, until smooth. Scrape side of bowl occasionally. Beat in sour cream. Pour evenly into pans. Tap pans on counter 2 to 3 times to eliminate air bubbles from batter.