Cut the butter into small pieces. Put in a 20 x 20cm microwavable glass or ceramic dish and cook in 20-second bursts in the microwave until melted. Remove, swirl it around the dish to coat the sides, then tip it into a mixing bowl.

Add the sugar to the bowl and, using a hand or electric whisk, whisk vigorously until the mixture is creamy and fully incorporated into the melted butter.

In a jug, stir the vanilla extract into the milk along with the beaten eggs. Whisk this, a little at a time, into the sugar and butter mixture, ensuring it’s thoroughly incorporated before adding more.

Sift the flour and cocoa powder together, then fold gently into the cake batter. Finally, stir in the milk chocolate chips.

Tip the whole mix into the buttered dish and smooth using a spatula to fill the dish. Cook for 5 mins or until the brownies are well-risen and slightly firm to touch. Don’t worry if they’re still a bit soft in the centre; they will continue to cook for several minutes once out of the microwave.

Put the hot dish onto a cooling rack and leave for at least 20 mins to firm up. Cut into 8 squares. Will keep in an airtight container for three days.