Pre-heat oven to 180°C/356°F.

Coat the inside of an 18cm cake tin with butter, dust with flour, then shake off the excess flour.

In a bowl, beat the egg yolks with ⅔ of the sugar until whitish and thick. Draw a ribbon with the whisk; it is ready when the ribbon disappears slowly.

In a separate bowl, beat the egg whites. When small bubbles form and the volume doubles, add the remaining sugar in 2-3 batches and continue to beat to make meringue.

When meringue is firm and forms peaks, it is ready.

Sift flour into the beaten egg yolk and fold in with a spatula.

Transfer ⅓ of the meringue to the batter and mix until smooth.

Fold in remaining meringue in 2-3 batches.

Pour in melted butter and fold several times; it's okay if the butter is not completely mixed.

Pour the batter into the cake tin. Drop the tin onto the workbench to settle the batter.

Cook in the oven for 25 minutes. Insert a skewer in the center; if wet, cook for an additional 5 minutes.

Remove from oven, drop the tin onto the workbench a few times to detach the cake, and place it upside down on a rack to cool completely.

If making syrup, combine syrup ingredients in a saucepan, bring to a boil until sugar dissolves, and let cool.

Whip the cream until soft peaks form. Wipe strawberries, remove stems, and halve 10 strawberries.

Slice the cooled sponge cake in half horizontally. Remove the top half and set aside.

Brush the cut surfaces of both sponge halves with syrup gently.

Spread about 3 heaped tablespoons of whipped cream over the bottom half and fill with halved strawberries.

Spread about 4 heaped tablespoons of whipped cream over the strawberries.

Place the top half of the cake on, syrup side down, and gently press to align.

Fill any gaps with whipped cream.

(Optional) Thinly coat the top and side with whipped cream and refrigerate for 10 minutes.

Fully cover the cake with remaining whipped cream, reserving about 4-5 tablespoons for piping.

Pipe remaining cream to make mounds around the edge of the surface and place a strawberry on each mound.