Preheat the oven to 180°C (350°F) with fan assist (convection).
Wash the apricots, pat them dry, then cut them in half and remove the pits.
Butter a gratin dish and arrange the apricot halves tightly inside, cut side facing up.
Split the vanilla pod in half and scrape out the seeds.
Melt the butter and let it cool slightly.
Break the eggs into a mixing bowl, add the sugar and vanilla seeds.
Whisk everything together until the mixture is frothy, but don’t try to triple its volume like you would for a sponge cake.
Sift in the flour and whisk well to avoid lumps.
Gradually incorporate the milk while whisking to obtain a smooth batter.
Add the melted butter and mix thoroughly.
Pour the batter gently over the apricots. The apricot halves will rise to the surface and float.
Optionally, sprinkle the top with sliced almonds.
Carefully move the dish and place it in the oven.
Bake for 45 minutes, or a little longer depending on your oven.
Check for doneness by inserting the tip of a knife into the center, it should come out clean or slightly moist, without any raw batter.
If the top browns too quickly toward the end of baking, place a baking tray on the lowest oven rack or cover the clafoutis with a sheet of parchment paper.
The clafoutis will puff up during baking and then sink as it cools, this is perfectly normal.
Enjoy it warm or let it cool completely. Wait until it reaches room temperature before placing it in the refrigerator.
Only unmold it once it is thoroughly chilled.
Apricot clafoutis is delicious served warm or cold, the choice is yours.
You can dust it with a light sprinkle of powdered sugar just before serving.