So, marshmallow. This is a versatile recipe that can be adapted to introduce flavour and colour. I've slightly adapted a Hugh Fearnley-Whittingstall recipe.
You will need:
2 egg whites
550g granulated sugar
2 sachets of powdered gelatine (about 25g)
4 tbsp icing sugar
4 tbsp cornflour
A little oil for greasing
Liquid/gel colouring of your choice
Put the sugar and 250ml water into a large pan, along with a sugar thermometer and heat gently until the sugar is dissolved. When all dissolved, turn the heat up until the sugar reaches 124C.
This can take a while, so now you can get on with all the other jobs -
Put a small bowl over a pan of simmering water, and add 125ml water and the gelatine. Stir/whisk until the gelatine is melted.Then remove from the heat and leave to cool.
Put the egg whites into a large bowl and whisk (preferably with a stand-mixer) until stiff peaks.
And lightly grease a 20cm square tin.
When the sugar has reached the correct temperature, take it off the heat and stir in the gelatine - it'll bubble up a bit.
Turn the mixer back on and slowly pour the sugar syrup onto the eggs. Beat until it's just pourable. At this point you could add in a few drops of your desired colouring (pink is popular).
Leave to set in a cool place (but not the fridge) for a few hours. Using a oiled knife to help ease it out, tip the marshmallow onto a light dusting of icing sugar mixed with some of the cornflour. Cut into whatever shapes you like.
Mix together the remaining icing sugar and cornflour. Toss the cut pieces in this mixture, and then it's ready to eat. Store in an airtight tin, lined with greaseproof paper.
Having made this quite a lot now, I decided to experiment this time, and just tipped half of this plain mixture into a tin. I added a few drops of peppermint essence to the remaining mixture, gave it a quick beat, then tipped it into another tin, then swirled a few drops of colouring in with a cocktail stick. This gave me two quite flattish slabs, but as it was a flavour experiment, I didn't mind how it looked really. Despite initial reservations, the peppermint marshmallow disappeared quickest, and so for Christmas I might crush some candy canes and press these into the mixture before it sets for something different.
Edit: I have now tried adding candy canes! I ground them in the blender with icing sugar and cornflour. Then used this dust to roll the marshmallow in. It's blunted my blender blades quite a bit, but tastes delicious. However, I don't think there's anything added (except expense and blunt blades) by doing this, so in future will just continue using peppermint essence.
I've also tried strawberry essence. But despite using half a bottle, I couldn't taste it in the marshmallow once set.