Rinse the dandelion petals under cold water and shake dry. Check that all green parts are removed.

Bring the water to a boil in a small saucepan. Add the petals, remove from heat, and steep for 20 minutes until the water turns golden.

Strain through a fine sieve into a clean pan, pressing the petals to extract all the liquid. Discard the petals.

Add the sugar and lemon juice to the petal water. Heat over medium heat, stirring until sugar dissolves, then simmer for 8 to 10 minutes until slightly thickened. It should coat a spoon lightly. Remove from heat and set aside.

Heat the oven to 175 C / 350 F. Grease a 20 cm / 8 inch round cake tin and line with parchment paper.

Beat the softened butter and caster sugar together for 3 minutes until pale and noticeably fluffy.

Add the eggs one at a time, beating well after each addition. If the mixture looks like it's splitting, add a tablespoon of flour and keep going.

Fold in the self-raising flour, salt, and lemon zest using a large spoon or spatula until just combined. Add the milk and fold again until the batter drops easily from the spoon.

Scrape into the prepared tin and level the surface. Bake for 28 to 30 minutes until the top is golden and a skewer inserted into the center comes out clean.

Remove from the oven. While the cake is still hot in the tin, poke all over with a skewer, going about halfway down. Brush or spoon 4 to 5 tablespoons of the warm dandelion syrup generously over the surface and let it soak in for 10 minutes.

Turn the cake out onto a wire rack. Brush with another tablespoon of syrup while still warm, then leave to cool completely. Drizzle with the reserved syrup just before serving.