Prepare the baking pan. Cut 9" x 9" parchment paper or slightly bigger than the tube pan. Fold the parchment paper in half. Fold into a triangle then fold in half of a triangle. Invert the pan and place the folded pointed triangle on top of the middle pan. Hold and cut the folded parchment paper on the edge of the pan, then cut the pointed end to fit the hole of the tube pan. Grease the inside bottom of the tube pan. Unfold the cut parchment paper and place it inside the greased tube pan.
Prepare the dry ingredients. Measure, spoon and level or weigh the cake flour. Add the salt and baking powder in the cake flour mix until well combined. Sift on parchment paper.
Prepare the wet ingredients. In a large bowl, add all the wet ingredients. Mix until blended.
Prepare the cake batter. Add the sifted dry ingredients to wet ingredients in four additions to avoid lumps and over mixing. Mix until smooth.
Prepare the Meringue. In a stand mixer bowl. Beat the room temperature egg whites and cream of tartar at high speed while gradually add sugar until stiff peaks.
Cut and Fold Method for Cake. Add the meringue to the cake batter in four additions. Use a spatula or scraper and scoop the meringue and add to the cake batter mixture. Do a scraping motion. Scrape around the bowl and move the spatula on the middle down the bottom of the bowl. Like cutting a cake batter, scrape, cut, and fold until no streaks of cake batter.
Removing big air bubbles. Pour the cake batter into the tube pan with parchment paper. Tap to release some big air bubbles in the cake mixture.
Bake the cake. Bake in preheated oven to 345°F for 45 to 50 minutes (do not open the oven before 40 minutes of baking time, the cake might collapse. You can CHECK the cake between 40 to 50 minutes of baking) or until the cake tester inserted comes out clean. Invert the tube pan on a cooling rack or use a bottle to cool the cake.
Cool the cake. Invert the tube pan on a cooling rack or use a bottle to cool the cake.