Using hand mixer, cream butter and remaining 1 1/2 cups sugar in large bowl. (bakinandeggs.com)
With an electric mixer on medium speed, beat butter and 1 cup sugar until light and fluffy, scraping down sides of bowl as necessary, 3 minutes. (myrecipes.com)
In large bowl, whisk remaining 1/2 cup sugar with eggs, yolk, vanilla, and salt. (seriouseats.com)