Preheat oven to 180 C/ 160 C fan and line a 12 hole cupcake tin with large cases.
Weigh out the butter and caster sugar in the Thermocook bowl, put the lid on securely and PULSE in 7 second goes, scraping down the sides of the bowl as needed, until the mixture is light and fluffy.
Add the remaining ingredients except for the cocoa powder and extra plain flour and select CHOP for 20 second. Scrape down the sides and CHOP again for a further 5 seconds, if required.
Measure out half the batter (approximately 330 grams) into a medium sized bowl.
Add the cocoa powder to the Thermocook bowl and CHOP for 5 seconds.
Add the vanilla and remaining 25 grams of plain flour to the mixture you've poured out into a separate bowl and whisk until combined thoroughly.
Alternately spoon the mixture into the cupcake cases until they are 2/3 full. Using a wooden skewer, draw lines through the batter until it forms swirls.
Bake for 25 minutes until golden and springy to touch. Transfer to a wire rack to cool completely.
Meanwhile, clean out the bowl of the Thermocook and fill with a few inches of cold water. Select BOIL and switch off when the water has boiled.
Break your chocolate into a small heat proof bowl and cover tightly in foil. You don't want any water to get into the bowl.
Place the bowl into the larger steamer and select STEAM. The automatic setting is for 20 minutes, but you can pause it every now and again, leaving the lid off, so that the chocolate melts.
Search for steampunk gear and cog images on Google and print off designs that you like. Place the print -out underneath the clear silicone mould of your Lekue Decomat (or use greaseproof paper).
Pour the melted, slightly cooled, dark chocolate into the Decomat pen fitted with the small nozzle and trace your cogs and gears. Leave to harden in a cool place (I put mine outside!).
To prepare the Madagascan bourbon vanilla buttercream frosting, place all the ingredients in the bowl of the cooled Thermocook and select CHOP for 20 seconds. Scrape down the sides of the bowl and CHOP for a further 5 seconds.
Frost the cupcakes using a large star shape nozzle and decorate with the chocolate cogs and gears. Store in the refrigerator until ready to serve.
Calories per cupcake - 533
Mum of three, daydream adventurer, OU Life Sciences graduate, occasional crafter, ex-pat Canadian & quite possibly Britain's most northerly food blogger.