Preheat your oven to 200 C and line a 12 hole muffin tin with paper cupcake cases.
Weigh your mixing bowl and keep a note of the number.
Cream together the butter and sugar until light and fluffy. Add the egg and vanilla and beat well.
Sift in the flour, add the milk and beat until well combined.
Weigh your mixing bowl with the batter in it, and divide the mixture equally in half. You should have two bowls with approximately 250 grams of batter in each one.
Add the cocoa powder to one half to make the chocolate batter.
For the chocolate, double chocolate, chilli chocolate, chocolate fudge and coconut chocolate flavours, measure out 1/6th of the final weight of your chocolate batter into a small bowl - approximately 40-42 grams of batter - one at a time, adding each of the flavourings before spooning into the prepared baking case. Take a note of where you've placed each flavour - jotting down a diagram helps.
For the gin & tonic, lemon, vanilla rose, vanilla and vanilla coconut flavours measure out 1/6th of the vanilla batter and add each of the flavourings one at a time. Spoon into the prepared baking cases.
For the peanut butter chocolate swirl flavour, measure out 25 grams of vanilla batter and stir in the peanut butter. Drop in small spoonfuls, along with 20 grams of chocolate cupcake batter into the prepared cupcake case. Swirl using a toothpick. Repeat for the toffee chocolate flavour.
Bake for 15-20 minutes until light golden and well risen. Transfer to a wire rack to cool completely.
Prepare your frosting by beating together the butter, icing sugar, vanilla and 4 tbsp double cream together. Divide the mixture evenly in half (weighing it out makes this so much easier) and add the cocoa powder and another tbsp of double cream to one half.
Measure out three 70-75 gram bowls of vanilla frosting. Add the gin & lime zest to one, the lemon juice to another and the rose syrup to the third. Pipe over the top of their respective cupcakes and decorate with a lime slice, lemon zest and pink chocolate curls. Frost the coconut vanilla and plain vanilla cupcakes with 70 grams of frosting and decorate.
Measure out two small bowls of 40 grams of chocolate frosting and set aside. Frost the chocolate, double chocolate, chilli chocolate, chocolate fudge and coconut chocolate flavours with the remaining icing and decorate with their respective decorations.
For the swirled frostings, add the peanut butter to 25 grams of vanilla frosting and swirl with one of the 40 gram bowls of chocolate frosting. Decorate with chopped American peanut butter candies. Repeat with the toffee swirl frosting, and topping with a drizzle of toffee sauce.