Preheat the oven to 350 °F or 180 °C. Prepare three 6 inches round cake pan with nonstick cooking spray or homemade pan release and set aside until ready to use.
In a medium bowl, sift the cake flour into it. Add baking powder, and salt to the flour and whisk together. Set aside.
In a large bowl with a hand mixer or a stand mixer fitted with the paddle attachment, cream the sugar and butter until light and fluffy about 3- 4 minutes. Scrape down the sides of the bowl and mix again for a minutes.
Add the eggs one at a time and mix well after each addition on a medium speed until smooth. Add the vanilla extract and mix well for 30 seconds.
Reduce the speed of the mixer and add a third of the dry ingredients, alternating with half of the buttermilk. Repeat with the dry ingredients and buttermilk until they are fully mixed. Add the last third of the dry ingredients and mix well. Stop the mixer and scrape the sides of the bowl and mix until smooth.
Divide the cake batter among the 3 prepared cake pan. Place the pans on the center rack of the oven and bake for about 30 -35 minutes or until a toothpick is inserted into the cake and comes out clean and dry. Bring the cake out of the oven and allow to cool in the baking pan for 10 minutes before transferring them to the cooling rack to cool completely