Make the fudge sauce. Place chopped chocolate, sweetened condensed milk and water in a medium heatproof bowl and microwave on 50% power in 20 second increments while stirring in between until melted and smooth. You can also melt it over a double boiler. Add cocoa powder and stir to combine. Set aside to cool slightly.
Make the ice cream. Mix cream cheese until smooth and creamy. Add sweetened condensed milk and mix until smooth with no lumps, then mix in yogurt, vanilla and peppermint extract thoroughly.
Place cold cream in a medium bowl and use an electric hand mixer (or a stand mixer fitted with a whisk attachment) to whip it until it forms soft peaks. This will take 2-3 minutes on medium-high speed.
Add the cream cheese mixture to the bowl with the whipped cream and fold it together until evenly blended.
Transfer half of the ice cream mixture to the prepared loaf pan, then spoon half of the fudge sauce over top. Repeat with the remaining ice cream and fudge sauce. Use a butter knife to gently swirl everything together a few times, but have some restraint as you want defined pockets of fudge in the ice cream. If you’re using a tall 1L freezer container, then add one third of the ice cream, followed by one third of the fudge sauce and then repeat these layers 2 more times.
Cover tightly with plastic wrap and place it in the freezer for at least 8 hours. Keep it tightly covered and enjoy it for up to 2 months. Let it soften in the fridge for about 10 minutes before scooping.