Preheat your air fryer to 160°C. Allow it to run for 5 minutes whilst you make the batter.
Put the air fryer on for 5 minutes whilst you are making the batter to preheat it. Add 100 g Butter and 150 g Chocolate to a bowl. Microwave on high for 30 seconds at a time, until melted together.
In a large mixing bowl, whisk 2 Eggs150 g Light brown sugar and 1 tablespoon Vanilla extract together, until light and fluffy.
Stir the chocolate mixture into the egg mixture.
Sift in 70 g Plain flour, 40 g Cocoa powder and 1 pinch Sea salt. Gently fold the dry ingredients into the wet mixture.
Stir in 50 g Milk chocolate chips.
Pour the mixture into a lined 7 x 4 inch baking tin and carefully place into your air fryer basket.
Cook at 160°C/320℉ for 25 minutes. insert a sharp knife or skewer and it should come out clean. Cook for 5 minutes more, if needed.
Notes
Make sure that the tin you are using fits in your air fryer basket. If you need to use a smaller tin to fit in, then you might need to adjust the amount of batter you can pour in and adjust the cooking time.
Once the air fryer brownies are cooked, you MUST chill them. Leave them to cool at room temperature and then put them in the fridge for 4 hours or the freezer for 2 hours. They will be too gooey to eat right away.
Don't over-mix your brownie batter, as that can cause them to crack.
Why not add in a handful of walnuts to the brownie batter? It will make them harder to slice neatly, but it's a delicious addition.
You can open your air fryer as many times as you like to see how the brownies are cooking. It won't affect how they cook.