Creamy cookie dessert with no-bake chocolate frosting

Preparation :

How to make the frozen dessert:

For the cream:

Put the condensed milk, cornstarch and milk powder in a saucepan.
Mix well to dissolve completely.
Add the milk, cream and butter, and heat over medium heat, stirring constantly, until it begins to boil and thickens.
Let it cook for another 2 minutes then remove from the heat.
Transfer this cream to a bowl, cover with plastic wrap and leave to cool completely.
Once cooled, add the whipped cream beaten into stiff peaks and mix gently to incorporate.
Remove from the heat, pour into a container and cover with plastic wrap until it is completely cooled so that we can add the whipped cream.
With the cream at room temperature, gradually add the whipped cream, mixing lightly.