In a bowl, whip together the sugar and the eggs. Then add progressively the flour, baking powder, almond powder, melted butter, almond extract, and two third of the slivered almonds. Put aside in the fridge for half an hour.
Preheat the oven to 460°F (240°C). Pour the batter in madeleines’ molds - or any silicon molds if you don’t own madeleine moulds. Don’t fill the moulds completely as the pastries will rise while baking.
Put the remaining slivered almonds on top then put in the oven for 5 min before lowering the heat at 350°F (180°C) for 5 more minutes. This technique should make the madeleines grow their peculiar bump on the top. The madeleines are ready when they start to turn golden.
A cup of green tea - floral, slightly tannic, or a small glass of amaretto, are a great pairing.