In a large mixing bowl, whisk together the sweetened condensed milk, Dutch process cocoa powder, and vanilla extract until smooth.

In a separate bowl, whip the heavy cream on medium speed until soft peaks form.

Gently fold one-third of the whipped cream into the chocolate mixture, then gradually fold in the rest.

Fold in the brownie pieces until evenly distributed.

Pour the mixture into an airtight container and smooth the top.

Cover and freeze for at least 12 hours or overnight.

Scoop and serve with optional toppings like whipped cream or chocolate syrup.