- Melt the butter in a small pan over medium heat. Stirring continuously, cook until golden brown and fragrant. Set aside to cool.
- In a medium bowl; whip eggs and sugar until thick and pale.
- Fold in all-purpose and hazelnut flours. Gently fold in extracts and cooled brown butter. Chill batter 2 hours or overnight.
- Preheat oven to 350˚F; butter and flour madeleine pan, tapping to remove excess flour.
- Fill each shell 3/4 full and bake 12-15 minutes until golden. Remove and cool on a wire rack.