Cut the butternut into pieces, pour some olive oil over it and bake for about 40 minutes in the oven at 180 °C or until the squash is cooked (see tip). Melt 150 g chocolate au bain-marie or in the oven at 50 °C and combine with the cooked still warm butternut in a sturdy blender (see tip).Blend until you get an even, homogeneous mass. Line a mold with baking paper and pour in the mixture. Let the chocolate mousse set in the refrigerator for half an hour to an hour (see tip).

Melt the remaining 100 g chocolate and stir in the coconut milk. Remove the chocolate mousse from the refrigerator. Remove the ring from the springform pan and carefully pull the baking paper off the side, but leave it on the bottom. Brush the cake with the chocolate mixture, both on the top and along the sides. Put back in the refrigerator until everything is firm. Although it can be tricky to wait, try to let the tart set in the refrigerator for at least an hour before you cut it. Serve it on the baking sheet.

Tip: Bake butternut in the oven or boil it?

For a firm chocolate mousse on the inside, it is better to bake the butternut in the oven. Cooking or steaming can result in too moist a texture, making it more like a soft chocolate mousse. This is also delicious, but it makes it harder to cut skewers from. The layer of chocolate you spread on top afterwards becomes quite firm in the refrigerator and holds everything together nicely.

Tip: Allow chocolate mousse to set in the refrigerator first

This is necessary to spread the chocolate layer on top afterwards.