Preheat the oven to 325°F (163°C). Spray a 12-cup Bundt pan with nonstick spray.
Peel the peaches. Slice one peach into wedges and place them in the bottom of the Bundt pan. Chop the remaining 3 peaches into bite-size cubes.
Mix the brown sugar and cinnamon in a small bowl with melted butter. Sprinkle over the peaches in the Bundt pan.
In a large mixing bowl, beat the butter on high speed for 2 minutes. Add the cream cheese and beat on high for an additional minute. Then add the sugar and beat on high speed for one more minute. Finally, add in the sour cream and vanilla extract and beat on high speed until smooth and creamy.
Add the eggs, one at a time, beating after each addition until the egg is fully incorporated. Scrape the sides of the bowl before adding the next egg.
Stir in the chopped peaches.
Add the cake flour, baking powder, and salt, and mix on low speed until the dry ingredients are just mixed in. DO NOT OVERMIX.
Pour the batter into the prepared Bundt pan. Firmly tap the pan onto the counter several times to remove any air bubbles. Then bake for 80-90 minutes, or until a toothpick inserted comes out clean.
Remove from the oven and cool in the pan for 1 hour. Invert onto a plate and cool completely. Serve with whipped cream and caramel sauce, if desired.