FOR THE ICE CREAM
Whisk together the condensed milk, vanilla and salt in a large bowl; set aside.
Whip the 2 cups of the cream with a mixer on medium speed until firm peaks form, about 2 minutes. And just until stiff peaks form, don't over beat the cream because it will separate and be ruined, so just beat between a minute and a half to two minutes.
Fold the whipped cream into the condensed milk mixture with a rubber spatula until combined and not lumpy,you can beat it lightly with a whisk to remove lumps. Pour into a chilled metal pan ( here I used a loaf pan) and swirl in the chocolate sauce ( recipe follows on step 6) using a metal spatula or butter knife.
Cover and place in the freezer for about 2 hours until thickened and set.
FOR THE CHOCOLATE SAUCE
Heat but do not boil the¼ cup heavy cream in a saucepan
When hot, add the broken up pieces of chocolate and let it melt into the hot cream
Stir over medium heat until the cream has reduced a bit and the sauce has thickened. Before placing the ice cream into the freezer, swirl the sauce into it.
FOR THE BROWNIES
Preheat oven to 170°C / 350°F.
Grease a 9x9 inch / 23cm square baking pan, and line it with baking paper.
Mix together the oil, sugar and vanilla extract.
Add eggs and mix until well combined.
Combine flour, cocoa, baking powder and salt. and then add to the egg mixture until well combined.
Pour the batter into the pan and spread evenly.
Bake for 25-30 minutes, or until a skewer inserted comes out clean with just a few crumbs
Allow to cool before cutting into squares
Serve warm with set ice cream.