1. Make the Caramel and Prep the Peaches: Melt sugar and butter to create the caramel, then arrange peach slices in the prepared pan.
2. Make the One-Bowl Cake Batter: Combine softened butter, sugar, eggs, vanilla, flour, cornmeal, baking powder, and salt. Stir in buttermilk until smooth.
3. Pour & Smooth the Batter: Gently pour the batter over the caramelized peaches and smooth the top with a spatula.
4. Bake the Cake: Bake at 350°F (175°C) for 45 minutes, or until a toothpick inserted into the center comes out clean.
5. Flip the Cake: Let cool for 10 minutes, then invert onto a serving plate and lift off the pan.
6. Serve Warm: Slice and serve warm, optionally with vanilla ice cream or whipped cream.
Notes
For the best flavor, use ripe but firm peaches. Let the cake cool slightly before flipping to ensure the caramel stays intact.