In a mixer bowl, whisk eggs with sugar, salt, and vanilla seeds until fluffy.
Add warmed milk (heated to 40°C), unsalted butter, and grapeseed oil. Mix with a whisk.
Sift in the flour and baking powder, then stir with a whisk. Cover the dough with plastic wrap and refrigerate for 12 hours.
Grease the madeleine mold with soft butter and dust it with flour.
Fill the madeleine molds with batter by ¾. Preheat the oven to 220°C / 428 °F, put the madeleines into it, immediately lower the temperature to 165 °C / 329 °F and bake them for about 6-8 minutes.
While the madeleines are still warm, fill them with pistachio praline. Then leave to cool at room temperature.
