These are such a treat – they taste just beautiful and look pretty divine too!
Preheat oven to 180C and line a 12 hole, 1-cup capacity muffin tin with paper cases.
Place the butterfly whisk and the egg whites in the Thermomix bowl and whisk 4 min/37C/speed 3/Measuring cup OFF until firm.
Remove egg whites and give your Thermomix bowl a quick wash.
Add the sugar and blitz on speed 9 for about 10 secs.
Add the butterfly and the butter and whip speed 4 for 30 seconds to 1 minute or until pale and fluffy.
Add the oil, yolks and vanilla and whip for another 30 seconds at speed 4.
Sift together the flour, corn or rice flour and cocoa powder.
Add in the dry ingredients and buttermilk and whip again for 10 seconds on speed 4, or until just combined.
Finally, fold in the vinegar and food colouring and add the egg whites, very gently folding by hand until combined.
Divide mixture among the cupcake cases and place in the oven to bake for 20 minutes or until firm to the touch.
Let cupcakes cool on a wire rack while you make the frosting.
For the frosting, combine all ingredients in the bowl of your Thermomix with the butterfly attachment and beat on speed 4 until smooth.
Transfer frosting into a snap-lock plastic bag and snip one of the ends off, pipe mixture on top of the cooled cupcakes and smooth the tops with a little spoon. Serve.