Preheat the oven to 170 degrees C and line a cupcake tray.

Place the butter, flour, sugar, baking powder and salt into a large bowl or the bowl of your mixer and mix until it resembles sand.

Place the milk, eggs and milkshake powder into a jug and whisk lightly.

Pour the milk mixture into the dry ingredients and mix on med-high speed until well incorporated and smooth.

Divide the batter between the cupcake cases, 2/3 full.

Place in the oven for 20-25 minutes until risen, slightly golden and an inserted skewer comes out clean.

Transfer to a wire rack as soon as possible to stop papers peeling away from cupcakes and leave to cool completely.

Once cooled, make the frosting. Sift the icing sugar into a large bowl or the bowl of your stand mixer and add in the butter.

Mix, starting on a slow speed and increasing as the mixture combines, until light and fluffy. Place the milk and milkshake powder into a jug and whisk until combined.

Pour into the buttercream and mix until well combined and perfectly smooth.

Pipe or spoon the frosting onto the cupcakes and place a milk bottle on top to garnish, if desired.

Cupcakes will keep in an airtight container in the fridge for up to 3 days.