In a small saucepan reduce the passionfruit juice over a low heat until it yields 2 teaspoons. Remove from the heat and allow to cool. In a saucepan combine the butter and honey, melt over a low heat and allow to cool. Whisk the eggs and sugar together until pale. Sift the flour and baking powder together and mix into the egg and sugar mixture. Add the ground almonds and mix until combined. Lastly, add the cooled butter and honey mix, then the passionfruit reduction and passionfruit pulp. Allow the batter to rest for at least 2 hours or overnight in the refrigerator prior to using it.
Preheat the oven to 180°C (350°F/Gas 4).
Brush madeleine trays with the extra melted butter then, using a spoon or piping bag, place the batter into the moulds until three-quarters full. Bake in the oven for 12-15 minutes or until cooked. Remove the trays from the oven and turn the madeleines out to cool. Dust with icing sugar or roll in caster sugar before serving. Madeleines are best served straight from the oven, when still warm inside.