Preheat oven to 350 degrees.
Prepare 9 x 13 pan with non-stick spray or butter.
In the bowl of a standing mixer, beat the sugar and butter for 2 minutes.
Add eggs one at a time.
Add vanilla.
Combine in a separate bowl the flour, baking powder and salt.
Add the flour mixture and the sour cream alternating beginning and ending with the flour.
Pour into prepared pan.
Top batter with a layer of sliced peaches.