Whisk eggs and sugar together over a lightly simmering pot until the mixture reaches 37-40°C.

Mix the egg mixture at high speed using a hand mixer until it forms ribbons that last for about 3 seconds.

Sift cake flour into the mixture and gently fold it in.

Line a baking pan with parchment paper, ensuring it covers the sides. Pour the batter into the pan and tap to remove air bubbles.

Bake at 175°C for 12 minutes. Remove the sponge sheet from the pan immediately and peel off the parchment paper.

Whip cold fresh cream with sugar at high speed until stiff peaks form.

Flip the cooled sponge sheet onto a new parchment paper and remove the old parchment. Trim the edges if desired.

Spread whipped cream evenly over the sponge sheet.

Place orange slices on top of the cream.

Roll the sponge sheet tightly using the parchment paper and secure with tape. Chill in the refrigerator for 10-30 minutes.