Gently clean the flowers of any debris, rinse them under running water and set aside.

In a large pan, heat the water and sugar over medium heat, stirring occasionally, until the sugar has dissolved.

Once it comes to the boil and the sugar has fully dissolved, remove from the heat and leave until warm to the touch.

Add the lemon zest and juice and the elderflowers, pressing them into the liquid with a spatula.

Cover and refrigerate for 3–4 days.

Strain through muslin or a fine sieve. Store in sealed bottles until needed.

Preheat the oven to 180°C (355°F) and line two 19cm tins with baking paper.

Beat the butter with the sugar until smooth and fluffy.

Add the eggs one at a time, mixing well after each.

Add the vanilla and mix again.

In a bowl, combine the sifted flour, baking powder and salt.

Fold the dry ingredients into the wet ones with a spatula.

Divide the batter evenly between the tins and level it.

Bake for 25–30 minutes, until the edges pull away from the tin and a skewer comes out clean.

Cool completely before turning out and removing the paper.

Whip the cold cream with the powdered sugar and vanilla until it starts to thicken.

Add the mascarpone and keep whipping until firm. Don't overwhip, or it may split.

Level the sponges if needed.

Place the first sponge on a serving plate and soak it with elderflower syrup diluted 1:5 (1 tablespoon of syrup to 5 tablespoons of water) – use less water for a stronger flavour.

Spread an even layer of chantilly, about 1.5cm thick, and scatter sliced strawberries on top.

Add the second sponge and repeat.

Decorate with strawberries and elderflowers, or as you like.