Preheat the oven to 140°C / 285°F top heat and 150°C / 300°F bottom heat.

Whisk the egg yolks, coconut milk, oil, and vanilla extract until smooth.

Whisk the cake flour into the yolk mixture until no lumps remain.

Beat the egg whites, lemon juice, salt, and sugar to medium peaks.

Fold one third of the whipped egg whites into the yolk batter.

Fold in the remaining whipped egg whites in two additions.

Weigh 50 g of batter and mix it with the cocoa powder.

Weigh 20 g of batter and mix it with the charcoal powder.

Transfer the cocoa batter and charcoal batter into separate piping bags.

Pipe leopard-pattern outlines into the chiffon cake pan.

Bake the patterned pan for 1 minute to set the design.

Pour the plain batter into the pan and tap the pan to release large air bubbles.

Bake for 15–17 minutes at 140°C / 285°F top heat and 150°C / 300°F bottom heat.

Lower the oven to 130°C / 265°F top heat and 140°C / 285°F bottom heat.

Bake for about 45 minutes until the cake is cooked through.

Remove the cake and tap the pan once on the counter.

Invert the pan and cool the cake completely before unmolding.