In a medium sized bowl whisk together the flour, baking powder, baking soda and salt. If using vanilla powder, add this to the bowl as well and mix well. Set aside.
Wash your peaches and cut two of them into chunks. Place in a blender and puree until smooth.
Take your other two peaches and cut them into chunks (the size of your chunks is really up to you). Place them in a small bowl and add 1 tablespoon of the flour mixture to the peaches. Toss to coat. Set aside.
Separate your eggs. Keep the egg whites to the side and add the egg yolks to the bowl of a stand mixer. To the egg yolks add the sugar and beat until well combined.
Next add the oil and the peach puree to the stand mixer bowl. Mix until all the ingredients are well combined. If you are using vanilla extract, add it to the contents of the bowl at this point as well.
Next add in half of the flour mixture; blend well and then add in half of the cream. Mix again. Follow this by adding the remaining flour and then the remaining cream. Mix well until everything is well combined.
Add the peach chunks to the cake batter and either using a rubber spatula or very slowly turning on the stand mixer, stir the peach chunks into the batter. Be careful if doing this with the stand mixer as you don't want to break apart your peaches.
In another bowl combine the egg whites with the cream of tartar and beat together until stiff peaks form.
Fold the egg whites into the cake batter using a rubber spatula.
Preheat your oven to 350 degrees Fahrenheit.
Prepare your cake pan by lining the bottom with parchment paper and greasing the sides with a bit of vegetable oil.
Pour the batter into the cake pan. Smooth the top with a rubber spatula or the back of a spoon.
Bake in the middle rack of your oven for 55 - 65 minutes or until a toothpick inserted into the center comes out clean.
When your cake is done, remove from the oven and let cool in the cake pan for 5 minutes before removing it and allowing it to cool completely on a rack.
While your cake is cooling, prepare your whipped cream.