Mix flour, sugar, and salt in a bowl.
Melt milk and butter together over medium heat.
Add the melted milk and butter mixture to the bowl and mix well.
Add eggs and vanilla bean, then stir to combine.
Pour in maple syrup and finish the dough.
Let the batter rest in the refrigerator for at least 12 hours.
Butter the canelé molds and fill them up to 90% with the batter.
Bake in a preheated oven at 190°C for about 60 minutes.
Cool before serving.