In a bowl, mix together the flour, baking powder, and salt. Set aside.
Using an electric mixer, whisk together the eggs, vanilla extract, Speculoos paste, and sugar.
Incorporate the dry ingredients, then the melted butter.

Cover the bowl and refrigerate for at least 3 hours.

Drop the batter by spoonfuls into madeleine molds and bake for 11 to 13 minutes in a preheated oven at 400°F (200°C).
Unmold and let cool on a rack.
Can be stored for about 2 months in an airtight container.