Make the Cake Batter

1. Preheat the oven to 160°C (325°F). Prepare an unlined 20 cm (8-inch) chiffon cake pan. Do not grease it.
2. In a medium mixing bowl, whisk the egg yolks and 28g sugar until pale and slightly thickened.
3. Add the vegetable oil, orange juice, and orange extract,  mix well until fully emulsified.
4. Sift in the cake flour, salt and baking powder, then gently mix until just combined.
5. Fold in orange zest, mix well and set aside.

Make the Meringue

1. In a clean, grease-free, bowl add the cream of tartar into the egg whites and begin whisking until foamy.
2. Gradually add 50 g sugar, one-third at a time, giving each addition 30 seconds to a minute to let the sugar dissolve.
3. Once all the sugar is added, turn the mixer to medium high speed and continue to whisk until stiff peaks form.

Combine the Mixtures

1. Scoop a small amount of the meringue and fold it into the egg yolk batter to lighten it.
2. Then pour the loosened cake batter back to the meringue, gently combining them using a whisk to maintain the airy texture.
3. Use a spatula to scrape down the sides and the bottom of the bowl to make sure everything is well incorporated.
4. Pour the batter into an ungreased chiffon pan (best poured in one spot).
5. Lift the pan a few inches and drop it onto the counter once or twice to release any large air bubbles.
6. Run a skewer through the batter to remove smaller air pockets for a finer crumb.  Shake the pan gently to smooth the top.

Bake and cool the Cake

1. Bake in a preheated oven at 160°C (325°F) for 30-35 minutes, or when an inserted skewer comes out clean.
2. Immediately invert the cake pan and let it cool completely upside down to prevent collapse.
3. Once cooled, gently run around the edges and the funnel of the pan with a spatula to release the cake.
4. Gently press around the base to release it from the bottom of the pan then run around the base of the pan with the spatula again to release the cake completely.
5. Prepare your serving plate or cake stand, then flip the tube pan upside down.
6. The cake should come out cleanly and beautifully.

Make the Orange Whipped Cream 

1. In a small bowl, mix the salt with the icing sugar and set aside.
2. Before whipping, place your mixing bowl in the fridge for 15 minutes.
3. Add chilled double cream, place a sieve on top of the mixing bowl, sift in icing sugar mixture.
4. Remove the sieve, add the orange juice, orange extract and orange zest in the cold bowl, whisk until stiff peaks form.
5. Cover and refrigerate until ready to use.
   

Decorate the Cake (optional)

1. Place the cooled chiffon cake on a cake stand.
2. Apply a thin layer of orange whipped cream to crumb coat the cake, then chill for 30 minutes to set.
3. Repeat the process for the final coat of whipped cream.
4. Pipe on top with any design of your choice (I chose a dollop effect), and garnish with fresh orange slices.
5. Slice and serve — enjoy your beautifully decorated orange chiffon cake!