Pour the milk into a saucepan, add the butter, and melt over medium-low heat.
In a bowl, add the egg yolks and sugar and mix well with a whisk.
Sift cake flour, almond flour, and salt together and mix in.
Slowly pour in the milk and butter mixture to form the batter.
Add vanilla extract and rum and stir well.
Cover with plastic wrap and let it rest in the refrigerator for at least 24 hours.
Butter the pan and pour in the batter.
Place the pan in a preheated oven at 200°C and bake for 20 minutes, then bake at 180°C for another 30–40 minutes.
Let it cool completely.