In a large bowl, whisk together the sweetened condensed milk and the vanilla.
Using a spatula, stir in the sifted cocoa powder, sifted light brown sugar and salt. This will get very thick. Keep stirring until fully blended.
In another large bowl, beat the heavy cream until soft peaks form. Using a spatula, stir in the thick chocolate sweetened condensed milk mixture. Keep folding in until completely combined. There should be stiff peaks at this point. If not, whisk again till stiff peaks form.
Use the spatula to fold in the cookie pieces. Pour into a 9 x 5 loaf pan. Sprinkle some more broken cookies on top, cover with plastic wrap then aluminum foil and freeze overnight before serving. Enjoy!