01 - Preheat the oven to 350°F. Grease and flour a 9-inch round cake pan or springform pan.
02 - In a medium bowl, whisk together the flour, baking powder, baking soda, and salt until well blended.
03 - In a large bowl, beat together the melted butter and sugar until smooth. Add the eggs one at a time, mixing well after each addition. Stir in the sour cream and vanilla extract.
04 - Gradually fold the dry ingredients into the wet mixture until just combined. Be careful not to overmix.
05 - Gently fold in two-thirds of the peach slices, ensuring even distribution throughout the batter.
06 - Pour the batter into the prepared pan and smooth the top. Arrange the remaining peach slices on top in a circular pattern.
07 - In a small bowl, mix the sugar and cinnamon. Sprinkle evenly over the arranged peaches.
08 - Bake for 38-42 minutes, or until a toothpick inserted into the center comes out clean and the top is golden brown.
09 - Let the cake cool in the pan for 10 minutes, then run a knife around the edge and release onto a wire rack to cool completely.
10 - Serve slightly warm or at room temperature, plain or with whipped cream.