Preheat the oven to 325 degrees F and line a pullman pan or 9x5 loaf pan with parchment paper.
In a small bowl, whisk together the flour, baking powder, and salt.
In the bowl of a stand mixer fitted with a paddle attachment, cream the butter and sugar together for 3-4 minutes until light & fluffy.*
Scrape down the bowl and turn the mixer down to low speed.
Add the eggs one at a time, scraping the bowl down in between each addition. Add the vanilla with the last egg.
Add half of the dry ingredients and mix until just combined.
Mix in the buttermilk and oil.
Then, add the rest of the dry ingredients and mix until just combined.
Scrape down the bowl one last time to make sure everything is evenly combined.
Pour the batter into the prepared pan, and smooth out the top.
Dip the thinly sliced peaches in flour and place on top of the batter, careful not to overlap them.
Sprinkle half of the streusel on top (more so on the edges than on top of the peaches).
Bake for about 30 minutes, then add the rest of the streusel on top, and bake for another 30-40 minutes or until golden on top and toothpick interred comes out with just a few moist crumbs.
Allow the peach cobbler pound cake to cool in the pan.
Slice & enjoy!