Preheat oven to 325 degrees. Spray one 8-inch round pans with nonstick spray, line the bottom with parchment paper, and spray again. Set aside.
In a medium bowl, whisk together the flour, baking powder, and salt. Set aside.
In the bowl of a stand mixer fitted with the paddle attachment, beat the butter and sugar on medium speed until light and fluffy, about 4 minutes.
Add eggs, one at a time, beating well after each addition and scraping down the sides of the bowl as needed. Stir in the vanilla.
Gradually add in the dry ingredients, alternating with the buttermilk, starting and finishing with the dry ingredients. Mix on low speed until just combined.
Evenly place the peaches on the bottom of your cake pan.
Gently spread the batter over the peaches.
Bake for 40 to 45 minutes, until toothpick inserted into the center comes out with a few moist crumbs on it.
Let cool in pans for 15 minutes, then remove to wire rack to finish cooling.