Grease and flour oblong pan, 13x9x2 inches, or two 9-inch or three 8-inch round layer pans.
Mix sugar, butter, eggs and vanilla until fluffy. Beat on high speed, scraping bowl occasionally, 5 minutes. Beat in flour, baking powder and salt alternately with milk on low speed. Pour into pan (s).
Bake until wooden pick inserted in center comes out clean, oblong 45-50 minutes, layers 30-35 minutes; cool.
Recipe by Amish 365 at https://www.amish365.com/bonnie-butter-cake-with-brown-sugar-frosting/