Preheat oven to 180°C (160°C fan-forced). Grease and flour two deep 20cm round cake pans. Line bases with baking paper. Sprinkle side of pans evenly with a little gluten-free flour; tap to remove excess.

Beat butter in a large bowl with an electric mixer until changed to a paler colour. Sift flour and ⅓ cup of the sugar together. Beat flour mixture and milk into the butter, in two batches, only until combined.

Beat eggs and egg whites in a clean small bowl with an electric mixer until thick and creamy. Gradually add remaining sugar, 1 tablespoon at a time, beating until sugar dissolves between additions. Gradually pour egg mixture into flour mixture with motor operating on low speed, only until combined.

Divide mixture between pans; bake for about 50 minutes or until a skewer inserted into the centre comes out clean. Stand cakes for 10 minutes; turn, top-side up, onto wire racks to cool.

Meanwhile, make chantilly cream: beat cream, icing sugar and vanilla in a small bowl with an electric mixer until soft peaks form.

Split cold cakes in half. Reserve 12 of the smallest strawberries for decoration. Reserve another two ripe strawberries for pink icing. Thinly slice remaining strawberries.

Spread one cake layer with one-third of chantilly cream. Top with one-third of sliced strawberries. Repeat layering, ending with cake.

Make pink icing: push the preserved ripe strawberries through a sieve into a small bowl. You will need 1 tablespoon of strained strawberry puree. Sift icing sugar into a medium bowl; stir in strawberry puree and the boiling water to make a slightly runny paste. Pour and spread the icing over top of cake.

Top with reserved whole strawberries.