Beat the butter at medium speed with an electric mixer for about 2 minutes or until soft and creamy. Gradually add 2 3/4 cups sugar, beating at medium speed for 5 to 7 minutes. The mixture should be noticeably lighter in color. Add the room-temperature eggs one at a time, allowing each egg to blend into the butter mixture before adding the next. Beat in the vanilla with the last egg. Pour in the flour mixture alternately with the milk, mixing until just incorporated.