For the chocolate with walnuts, break the walnuts into smaller pieces, toast them gently in a non-stick pan, stirring constantly, until fragrant, then immediately remove from the pan, tip onto a plate and leave to cool.
In a small saucepan, heat the cocoa butter and coconut blossom sugar until the sugar crystals have dissolved. Stir in the cocoa powder very well.
Pour the mixture into a suitable silicone mold. Sprinkle the nuts on the still liquid chocolate and let the chocolate with walnuts solidify in a cool place.