For key visual process photos, refer to the body of the blog post.

Make the black sesame chiffon cake:

Cup of Yum
1. Preheat oven to 375°F/191°C.
2. Prepare a 9" by 13" baking sheet by lining it with parchment paper. Set aside.
3. In a large bowl, add in the egg yolks, 40g granulated sugar, pinch of salt, vegetable oil, milk, black sesame powder and vanilla extract.
4. Whisk until combined.
5. Sift in cake flour and stir or whisk until just incorporated. Set aside.
6. In the bowl of a stand mixer fitted with a whisk attachment, add in the egg whites and begin whipping on medium-low speed until foamy.
7. Add in cream of tartar, and gradually increase the speed.
8. Gradually add in the remaining 40g granulated sugar, and continue whipping until the egg white meringue reaches soft peaks.
9. Take about ⅓rd of the whipped egg white meringue and fold it into the black sesame egg yolk batter to lighten using a spatula.
10. Continue folding in the egg whites in ⅓rd additions, until all incorporated into the batter.
11. Pour batter into the prepared baking tray.
12. Give the tray a few taps on the counter to release any trapped air bubbles.
13. Smooth the surface with an offset spatula.
14. Bake at 375°F/191°C for 13-15 minutes, or until the top of the cake is springy and dry to the touch.
15. Remove the cake from the oven and give the tray a bang on the counter to prevent the cake from shrinkage.
16. Transfer the cake to a wire rack to cool (but not completely).

Make the whipped cream:

1. While the cake is cooling, prepare the whipped cream.
2. Tip: Using a chilled bowl (kept in the fridge) can help the cream whip up nicely.
3. Pour the heavy cream into the chilled bowl, add the powdered sugar, and whisk until stiff peaks form.
4. Note: Be careful not to overwhip the cream, or it may transform into butter.

Assemble:

1. Place the slightly warm cake onto a large piece of parchment paper, with the top side down (the browned exterior).
2. Dollop the whipped cream onto the surface of the cake.
3. Use an offset spatula to evenly spread the whipped cream over the entire cake.
4. Sprinkle on black sesame seeds (if using).
5. Beginning at the short end, use the parchment paper to assist in carefully rolling up the cake.
6. To ensure a tight roll, use the parchment paper to gently press and secure it.
7. Place the roll seam-side down and seal the ends of the parchment paper.
8. Transfer the cake to a tray and refrigerate for at least 4 hours to allow it to firm up.
9. Once chilled, use a serrated knife to trim off the cake ends.
10. Tip: To keep the slices clean, wipe the knife with a damp, warm towel between each cut.Cut the cake into thick slices and serve.