In the bowl of a stand mixer fitted with the whisk attachment, whip the heavy cream until medium-stiff peaks form.
In a separate mixing bowl, combine the sweetened condensed milk, cocoa powder, vanilla extract, and sea salt. Whisk until the mixture is smooth and no traces of cocoa powder remain.
Carefully fold the condensed milk mixture into the whipped cream using a rubber spatula, taking care not to overmix to preserve the volume of the whipped cream. Gently fold in the brownie pieces.
Pour the ice cream mixture into a 9x5-inch glass loaf pan (or freezer safe pan) smoothing it into an even layer. Cover tightly.
Place the pan in the freezer and allow the ice cream to set for a minimum of 8 hours before serving. Enjoy!