Christmas baking: Candy Cane Cupcakes

My year 10s are hardcore. We had a discussion in which I gave them the option of stretching out their final piece of coursework over two lessons or doing it all on the last day of term, and they opted for the latter. So, I baked them something I hoped would be amazing. And they lived up to it, too: they worked in silence for an hour on the essays. I hope they're decent.

Makes about 28 decorated cupcakes, because that's how many I needed for my class. It actually made 42 cakes but the icing only stretched to 28.

Ingredients:
Bark:
36 candy canes
200g white chocolate
A bit of peppermint extract
Cakes:
100g cornflour
6 tbsp cocoa
200g soft brown sugar
450ml cold water
300g unsalted butter, cubed
250g dark chocolate, broken small
1 tbsp vanilla extract
4 large eggs
250g caster sugar
250g plain flour
5 tsp baking powder
Icing:
250g unsalted butter
500g icing sugar
A bit of milk
Peppermint extract
Red food colouring

First, the bark (night before, ideally).
Snap about 3 inches of stem off each candy cane - leave behind a short candy cane which will decorate a cake (see picture). Crush the cane stems (I also added some of the canes themselves to this since I only needed 28 toppers). Melt the white chocolate carefully in a microwave. Stir in a few drops of peppermint - you don't (imo) want an overwhelmingly minty flavour. Add the crushed candy cane, stir and turn onto a lined baking sheet - I poured mine into my silicone brownie pan. Leave to set.

Make the cakes. This is almost Dan Lepard's chocolate custard muffin recipe (a fave), scaled up. Put the cornflour, cocoa, brown sugar and water into a saucepan and whisk together over a medium heat until boiling, very thick and smooth. Remove from the heat, beat in the butter and chocolate until melted and absorbed.

Transfer the chocolate mixture to your and beat until smooth. Whisk the eggs with the vanilla and, with the beater running, pour into the chocolate custard, followed by the sugar.

Measure the flour and baking powder into a bowl, stir together, then add to the custard and beat through until combined. Spoon into paper muffin cases; bake at 180C for 25 minutes.

Make the buttercream - whisk the butter until fluffy, then add the icing sugar a bit at a time. Add some milk if it gets too thick. Add red food colouring as desired: I had it in mind to make brilliant white mint icing for these but Mr Z brought me home golden icing sugar (which actually had a delicious depth of flavour) and I didn't have any green colouring in, so I dyed mine red. It's worth noting that the red hue continued to develop for some time after the cakes were iced, so less is more.

Pipe the buttercream onto the cooled cakes, then top with a candy cane and a piece of bark.

Next time I might try royal icing. I think something crisp and white is a great indicator of mint. I know the Americans think mint is red but it should really be green or white, shouldn't it?