1. Preheat the oven to 180˚C/160˚C/gas mark 4 and place 10 paper cases into two 12-cup muffin tins.
2. Place the butter and chocolate in a bowl set over a pan of simmering water, ensuring the bottom of the bowl doesn’t touch the water. Allow to melt, then remove from the heat and stir to combine until smooth.
3. In a bowl, combine the flour, sugar, cocoa powder, bicarbonate of soda and a pinch of salt.
4. In a jug, whisk together the eggs and red wine. Add the egg mixture to the dry ingredients, then stir in the chocolate mixture.
5. Add 100ml boiling water and whisk until smooth. Divide the batter between the prepared muffin cases and drop two blackberries into each one. Bake for 35 minutes or until a skewer inserted into the centre of a cupcake comes out clean. Transfer to a wire rack and allow to cool.
6. For the icing, place the blackberries in a blender or food processor and whizz into a purée. Pass the purée through a sieve to remove the seeds, pushing as much as possible through the sieve using a wooden spoon.
7. In a bowl, use an electric whisk to beat the mascarpone for one minute.
8. Add the icing sugar and three tablespoons of the blackberry purée. Continue beating until fluffy, scraping down the sides as necessary. Do not over-mix.
9. Slowly beat in the double cream and keep beating for 1-3 minutes until the mixture is light and fluffy.
10. Transfer the blackberry mascarpone into a piping bag and pipe a swirl on top of each cupcake.

Per Serving: 247kcals, 8.6 fat (5.2g saturated), 40.1g carbs (26.7g sugars), 2.8g protein, 1.7g fibre, 0.129g sodium