For the caramel:
Place in a tin ( biscuit-tin with cover, around Ø16cm and 8cm high) the sugar and the water.
Place the tin on the stove on the lowest fire and let the sugar cook until it becomes a light caramel (honey color)
Once you reach this point move the caramel around the complete tin (also the sides).
Sprinkle with raisins to taste.
Mix in the blender the condensed milk, the milk, the eggs, rum and the vanilla.
Add this mix to the caramelized tin and cover it with the lid.
Lay the tin in a pressure cooker and add water until half the tin (the water lay in the pressure cooker and NOT in the biscuit-tin).
Close the pressure cooker and bring it to cook, follow the instruction of the pressure cooker and let it cook for 20 min.
After taking the tin out of the pressure cooker let it cool-down until room temp.
Remove the quesillo from the tin.
Lay the quesillo on the fridge for around three hours before serving it.