Toast 180g walnuts in a dry skillet over medium heat for 4 to 5 minutes, stirring often, until fragrant and lightly browned.

Cool completely, then chop roughly. Set aside 100g for the batter and 80g for the topping.

Heat oven to 170C/340F. Grease a 9-inch (23cm) round cake pan and line the base with parchment.

Whisk the eggs and sugar in a large bowl with an electric mixer on high for 5 to 6 minutes, until pale, thick, and tripled in volume.

Warm the honey until runny, then drizzle it into the egg mixture with the vanilla, whisking briefly to combine.

Sift the flour, baking powder, and salt over the egg mixture. Fold gently in three additions until just combined.

Stir 2 to 3 tablespoons of batter into the melted butter and milk to loosen, then fold this back into the main batter along with the 100g toasted walnuts.

Pour the batter into the prepared pan and smooth the top. Bake for 32 to 35 minutes, until the top springs back when pressed and a toothpick comes out clean.

Cool the cake in the pan for 10 minutes, then turn out onto a wire rack to cool completely, about 1 hour.

Warm the honey with the water in a small pan over low heat until thin and pourable, about 2 minutes. Cool slightly.

Whip the cold heavy cream with the honey to soft peaks, 2 to 3 minutes on medium speed. Do not overwhip or the cream will turn grainy.

Slice the cooled cake horizontally into two even layers using a serrated knife.

Brush the cut sides of both layers with the honey syrup.

Spread half the honey whipped cream over the bottom layer and scatter with a third of the reserved walnuts. Top with the second layer.