Melt ¼ cup butter; pour into an ungreased 9-in. round baking pan.
Sprinkle with brown sugar. Arrange peach slices in single layer over sugar
In a large bowl, cream sugar and remaining butter until light and fluffy, 5-7 minutes. Beat in egg and vanilla. Combine the flour, baking powder and salt; add to creamed mixture alternately with milk, beating well after each addition. Spoon over peaches.
Bake at 180 for about 45 minutes. Cool for 10 minutes before inverting onto a serving plate. Serve warm.
