Butter Cake (Thermomix)

Ingredients:

250 g salted butter, softened (room temperature) and cut in cubes 
150 g low GI brown sugar
½ tsp natural vanilla extract
5 eggs, A size
50 g fresh milk
250 g self-raising flour

Preparation:

1. Preheat oven to 170°C. Line a 20 cm x 20 cm square cake tin with baking paper. Set aside.
2. Crack eggs into a bowl, weigh in milk and vanilla extract. Set aside.
3. Pour brown sugar into mixing bowl. Mill at 10 sec, speed 10 and turn into icing sugar.
4. Insert butterfly whisk. Place butter and sugar in mixing bowl, beat 1 min 30 sec/speed 3.0.
5. Mix 40 sec/speed 3.0, adding vanilla extract, eggs one at a time and fresh milk through hole in mixing bowl lid onto rotating blades to beat the mixture into a smooth batter.
6. Add self-raising flour, mix 30 sec/speed 3. Remove butterfly whisk.  Don't extend mixing time even if you see there's flour not mixed well. Just use spatula to mix lightly with batter.
7. Transfer cake mixture to prepared square cake tin.
8. Bake for 45 minutes (170°C), top and bottom heat (no fan!) or until a cake tester skewer or toothpick comes out clean when it is inserted in the centre of the cake. Allow to cool in cake pan for 10 minutes. Transfer to a serving plate and let cool completely. Cut and serve.