Blend the baked pumpkin into a smooth purée. Let it cool completely.

Weigh the eggs in their shells (about 55g each) for the number of eggs you plan to use, then weigh out the same amount of caster sugar. For the flour, use the same weight as the eggs minus 40g, and make up that difference with cocoa powder.

Allow 2 tablespoons of hot water per egg. Whisk the egg yolks with the sugar and water. Once the mixture has thickened and the sugar has dissolved, whip the egg whites into stiff peaks and fold them into the batter alternately with the flour and cocoa.

Pour the sponge batter into a greased and flour-dusted baking tin. Use a round springform tin with a diameter of 26 cm.

Bake in an oven preheated to 175°C (160°C fan). Baking time depends on the size and height of the sponge, but it's usually somewhere between 30 and 50 minutes. Don't open the oven during the first half hour, or the sponge may sink.

After this time, you can open the oven and insert a skewer into the centre of the sponge. It should come out clean.

Let the sponge cool thoroughly, then slice it horizontally twice to create three even layers.

Roughly chop the walnuts and place them in a pan together with the sugar. Heat gently until the sugar melts, coats the walnuts and starts to caramelise.

Remove from the heat and let cool, then blend in a food processor. You'll end up with a mix of coarse and fine crumbs with an amazing, spot-on flavour. Use this caramelised walnut crumb both inside the cake and for decoration.

Whip the mascarpone together with 200g of pumpkin purée and honey. Feel free to add a bit more honey to taste.

Divide the cream into two portions. Spread one portion over the bottom sponge layer, then sprinkle with some of the caramelised walnuts. Top with the middle sponge layer, spread with the second portion of cream, sprinkle with walnuts again, and finish with the top sponge layer. Place in the fridge.

Pour the cream into a saucepan and bring to the boil. Remove from the heat and break the chocolate into it. Leave undisturbed for ten minutes.

Then whisk until smooth. Let the cream cool at room temperature, then chill it in the fridge. Use the chilled cream to decorate the whole cake.

Finely grind the walnuts, then add icing sugar and 60g of pumpkin purée. Stir with a spoon and chill in the fridge. If your purée is a bit watery, you may need to add more sugar or walnuts. You're aiming for a mixture that can be shaped by hand.

Take a small piece of the dough at a time. Roll it into a ball in your hands, then flatten it slightly so it resembles a pumpkin. Make an indent in the centre and a small hole for the stem. Use a wooden toothpick to score ridges into the sides to finish the pumpkin shape.

Shape a small piece of the nutty mixture into a little roll for the stem – or you can make it from a piece of chocolate instead. Arrange the little pumpkins nicely on top of the chocolate-covered cake. Finish by sprinkling the remaining caramelised walnuts over the top.

Chill in the fridge until the next day before serving.