Place the flour, salt, baking powder, baking soda, nutmeg and cinnamon in a medium bowl and whisk until the ingredients are well combined, about 30 seconds.
Place the sugar and butter in the bowl of a stand mixer. Beat the butter and sugar mixture on medium speed until light and fluffy, about 4 minutes.
Add the eggs one at a time, beating on medium speed after each addition until each egg is thoroughly incorporated. Add the vanilla extract and mix on medium speed for about 10 seconds.
Add half of the flour mixture and mix on low speed until well combined. There may be some flour on the sides of the bowl - that is okay. Add all the sour cream and mix on low speed until combined. Add the remaining flour and mix on low speed until incorporated. Scrape the sides and bottom of the bowl and mix for another 10 seconds to ensure all the ingredients are well combined. If there is still flour clinging to the sides of the bowl, scrape the sides of the bowl with a silicone spatula and mix in the remaining flour by hand.
Gently place the cake batter on top of the peaches in 4 large dollops and gently spread the batter across the berries with an offset spatula. Bake until a cake tester comes out clean, about 45 minutes. Let the cake cool in the pan for 10 minutes. Run a knife around the edges to release the cake and invert in onto a platter.
Once the cake has cooled serve it with whipped cream or ice cream.