Preheat oven to 325 degrees F (162 degrees C).
Sift All-Purpose Flour (2 cup) three times into a mixing bowl.
Sift flour the final time into a large mixing bowl, then sift in Baking Powder (1 1/2 teaspoon).
Into the bowl of a stand mixer fitted with a paddle attachment, add Salted Butter (1 cup) and Granulated Sugar (1 cup). Cream together for 8 minutes, gradually increasing the speed and scraping down the sides of the bowl as needed.
Add Egg (4) one at a time, beating well after each addition.
Add half of the dry ingredients into the stand mixer. Mix until partially incorporated.
Add Buttermilk (1/3 cup) and Vanilla Extract (1 1/2 teaspoon). Mix to combine, then add the remaining dry ingredients. Mix until batter is smooth.
Transfer batter to a greased 8 by 12-inch loaf pan. Smooth out.
Bake for 55 minutes to 1 hour. Don't open your oven to check during the first 50 minutes.
Allow cake to cool completely inside the pan.
Dust the top of the cake with Powdered Confectioners Sugar (to taste). Slice and serve.