Line a 7"x10" brownie tin with parchment paper and leave to the side.
Add your milk chocolate and Kinder chocolate to a microwaveable proof bowl, and melt carefully. I do it in bursts of 15-30 seconds in the microwave.
Alternatively, use a large bowl and a double-boiler, and melt that way.
Once melted, add your condensed milk, and stir until smooth. Add in your icing sugar and stir again!
Chop up your Kinder Bueno, and mix into the fudge.
Pour into the tin, and leave to set fully.
Enjoy!
Notes
This will last in the fridge for 2 weeks!
You can use milk, dark or white chocolate along with the Kinder chocolate, or use all milk/dark/white. I wouldn't recommend using all Kinder.
The Kinder Bueno will eventually go soft but it's not the end of the world.
Recipe updated August 2019 - original used 350g milk and 350g kinder chocolate, but it was often splitting for readers. You can still make it, you just need to make sure it doesn't get too hot and it won't split!
Using icing sugar is optional - but without I would use 100g more milk chocolate!