Preheat the oven to 170C (340F) and line a cupcake tin with 12 cupcake liners.

Beat the butter and sugar and a medium speed using a stand mixer or an electric whisk until light and fluffy. Beat in the eggs one at a time and add 1 tbsp of flour with each egg. Then beat in the remaining flour and stop mixing as soon the mixture just comes together.

Put the instant coffee into a small bowl and place a tsp of cold water into the same bowl. Mix the instant coffee with the water until it has become a syrupy texture with no coffee flecks remaining. Add it to cake mixture and beat until the coffee has just incorporated throughout the batter.

Spoon into the prepared cupcake liners and fill each halfway full with batter. Bake for 17 minutes or until a skewer comes out clean. Transfer and cool on a cooling rack.

While the cupcakes are baking, prepare the milk icing. In a small saucepan, put in the flour, milk and sugar and whisk well. Place the saucepan on a medium heat and heat to a simmer while whisking frequently. It should become very thick and porridge like.

Remove from the heat and whisk in the vanilla extract and salt. Place some clingwrap over the top of the surface so that a skin won't form. Place in the fridge to cool to room temperature quickly.

When the milk mixture has cooled to room temperature, you can continue with the milk icing. Place the butter in a stand mixer or use an electric whisk, then beat the butter at a medium high speed by itself for a minute or two to soften it further. Add a tablespoon of the milk mixture at a time and continue beating at a medium high speed. Stop beating once the mixture becomes light and fluffy.

Pipe the icing on the cupcakes, I used a large star nozzle. Once done, dust with some cocoa powder. Store in an airtight container for up to 2 days at room temperature or 5 days in the fridge.