Preheat the oven to 350 F (180 C).
Deposit the Brazil nuts on a baking sheet and roast them lightly in the oven for 8 to 10 minutes.
Chop them coarsely once they have cooled.

Butter a 1.2 liter pudding mold or a 1.2 liter bowl and place a circle of parchment paper at the bottom.

In a small bowl, mix the flour, baking powder, and salt.
In a large bowl, cream the butter and sugar until the mixture is pale and light, about 2 to 3 minutes.
Add the eggs and mix.
Add the flour mixture, folding with a spatula.
Incorporate the clementines, their juice, and zest, the Brazil nuts, and the vanilla extract.

Pour the preparation into the mold.
Place a circle of parchment paper or buttered parchment paper on top.
Cover with the mold lid or aluminum and seal the edge with a string.

Boil water in a large pot.
Place the pudding mold in the boiling water. The water should be 2/3 of the mold.
Cover the pot and cook over low heat, letting it simmer until the cake has risen and is firm, about 75 to 90 minutes.

Serve warm with a drizzle of chocolate sauce or an orange sauce or vanilla ice cream.
Keeps in the refrigerator, well wrapped in plastic wrap, for up to a week.