Mix together the milk and apple cider vinegar and set aside for 10-15 minutes. The mixture should curdle very slightly.
Preheat the oven to 160°C for a fan-assisted oven or 180°C for a gas oven. Line two 12 cupcake baking trays with paper cases.
Sift together all the dry ingredients for the cupcakes leaving the sugar out for now. Set aside.
Whisk the milk/vinegar mixture with the rest of the wet ingredients for 4-5 minutes.
Slowly incorporate the dry ingredients into the wet mixture in three stages. Handle carefully and only combine as much as is absolutely necessary. We do not want to overwork it. The mixture shouldn't have large lumps but it doesn't have to be completely smooth.
Using an ice cream scoop, fill each cupcake case with batter (it should be halfway up the paper case).
Bake for 25 minutes or until a skewer inserted into the middle of a cupcake comes out clean. Don't be tempted to open the oven door for the first 20 minutes of baking.
For the chocolate frosting, whip together all the ingredients until light and fluffy (about 5 minutes).
For the rose frosting, whip together all the ingredients until light and fluffy (about 5 minutes).
When the cupcakes have cooled, fill a piping bag fitted with a large star nozzle with chocolate frosting on one side and rose frosting on the other. Pipe your pink and brown swirled cupcakes.