Put the can of condensed milk in a pot, cover with water and let it boil for 3-4 hours, topping up with water if needed, to keep the can covered with liquid. Allow to completely cool and then open it.
Boil the pudding according to package directions, using the boiled milk with sugar to taste. Leave to cool, after it thickens.
Beat the butter with condensed milk (at room temperature) into a smooth cream, then add 1 teaspoon brewed coffee (more if desired).
In parts, start adding the cooled pudding to the butter cream while continuously whipping.
The resulting caramel cream can be used for various cakes, or distributed into cups with biscuits or biscotti.
Garnish with crushed caramelized walnuts or grated chocolate.