Creating your Peach Blueberry Cake is a simple process if you follow these clear steps:

1. Preheat Oven: Preheat your oven to 350°F (175°C). Grease and flour a 9-inch round cake pan.
2. Mix Dry Ingredients: In a mixing bowl, combine the flour, baking powder, baking soda, salt, and cinnamon (if using). Set aside.
3. Cream Butter and Sugar: In another bowl, cream together the softened butter and granulated sugar until light and fluffy.
4. Add Eggs and Vanilla: Beat in the eggs one at a time, then stir in the vanilla extract until well combined.
5. Combine Wet and Dry Ingredients: Gradually add the dry ingredients to the butter mixture, alternating with buttermilk until just combined.
6. Fold in Fruits: Gently fold in the diced peaches and blueberries, ensuring they are evenly distributed throughout the batter.
7. Pour and Bake: Pour the batter into the prepared cake pan and smooth the top with a spatula. Bake for 30-35 minutes or until a toothpick comes out clean when inserted in the center.
8. Cool the Cake: Once baked, remove from the oven and let it cool in the pan for 10-15 minutes before transferring it to a wire rack to cool completely.
9. Dust with Powdered Sugar: If desired, dust the cooled cake with powdered sugar for a lovely finish before serving.

By following these steps, you will effortlessly create a Peach Blueberry Cake that is as delicious as it is beautiful!