Preheat the oven to 350 F (180 C).
Prepare 6 coffee cups with milk on a baking sheet.

Caramel with flaky sea salt:
Heat the cream until it boils.
Off the heat, add the brown sugar and mix until it is well dissolved.
Add the butter and flaky sea salt and mix well. Reserve.

Cake:
In a bowl, mix the dry ingredients. Reserve.
With the electric mixer, cream the butter and sugar.
Add the eggs one by one and mix well.
At low speed, add the dry ingredients, milk, and vanilla in alternation and mix until homogeneous.

Pour the preparation into the 6 cups, then pour the caramel with flaky sea salt over the cake batter.
Bake for 25 minutes.
Wait 15 minutes before serving.