Preheat the oven to 300 degrees F and grease a large bundt pan generously with cooking spray.
In a large mixing bowl, cream together the butter, sugar and cream cheese until combined. Then add in the eggs, one at a time, mixing after each egg. Then add in the vanilla extract.
Next gradually add the flour, 1/2 cup at a time and mix on low speed. Scrape down the sides of the bowl and mix ensuring that the batter is fully mixed together. Then mix in the salt.
Gently fold the diced peaches into the cake batter. Set the batter aside while preparing the cake topping.
Melt the butter in a small bowl and then mix it with the brown sugar. Place the sliced peaches in the bottom of the greased bundt pan. Then cover the slices with the brown sugar and melted butter mixture.
Pour the cake batter on top making it as even as possible. Gently tap the bundt pan on the work surface to eliminate any large air bubbles.