Make the cupcakes, sift the flour and baking soda in a large bowl. Set aside. Preheat the oven to 175 C and line 9 muffin moulds with cupcake liners. You could also make 10 smaller cupcakes.
Melt the chocolate till smooth in a double boiler or microwave (in 10 second increments, stirring in between each). Set aside to cool.
In a large mixing bowl, beat the butter and sugar till pale and fluffy with a hand mixer on low to medium speed. Next, beat in the egg and vanilla. Add the melted chocolate, and stir by hand till combined but do not over-mix.
Now add the flour mixture gradually, alternating with the boiled water. Stir gently, using a silicone spatula if you have one, avoiding lumps as much as possible. If you do see any lumps, run a hand mixer through the batter. The batter should be smooth and a little runny.
Divide the batter equally among the muffin moulds, filling them just about 3/4th of the way, and bake for 25 to 30 minutes until they have risen, developed slightly crackly tops and a toothpick poked in the center comes out clean.
Allow the cupcakes to cool in the tray for 10 minutes and then place them on a wire rack to cool completely. They will fall slightly as they cool and have fairly flat tops. Before you frost the cupcakes, refrigerate them for 30 minutes as this batter makes deliciously soft, but somewhat fragile cakes.
Make the salted caramel. For the caramel, choose a saucepan that doesn’t burn easily. On low heat, melt the sugar, stirring constantly. Do not do ANYTHING else during this step. Watch the sugar like a hawk. It will begin to form lumps and look gritty after about a minute. Slowly you’ll see it melting down, going from clear to amber pretty quick. Stir till it melts down completely.
Add the butter and stand back because it will splutter and bubble up a bit. Stir again till the butter melts into the sugar. Now add the cream gradually and watch out for more spluttering and bubbling.
Once the cream has blended in, allow the sauce to boil for 1 minute. It will rise and froth some more. Turn off the heat, carefully taste and stir in and extra pinch of salt if desired. Let it cool at room temperature.
Transfer to a clean jar and refrigerate till you're ready to use the caramel. Bring it back to room temperature, then gently reheat on the stove or microwave to get it to a 'drizzle-able' consistency when you're assembling the cupcakes.
Make the frosting. Beat the butter and peanut butter in a mixing bowl with a hand mixer on medium speed till smooth and creamy. Add the cream and vanilla and beat until light, then sift in the icing sugar.
Stir briefly to combine so the sugar doesn't fly everywhere, then beat with the mixer until smooth and fluffy. Taste and add more sugar to thicken further (I avoid this as it becomes too sweet for my taste). If the frosting is a bit soft, you can refrigerate it for 15 minutes. If not using it immediately, make sure you let it sit at room temperature for 10 minutes so that it is spreadable.
Assemble the cupcakes. Spread the frosting on the top of each cupcake (if you prefer to pipe, make sure the frosting is cold from the fridge but spreadable), then drizzle with the caramel (making sure it's not hot so the frosting doesn't melt!) and finally, top with the chopped peanuts. Enjoy!
These cupcakes need to be kept refrigerated at all times. Store in an airtight box in the fridge for 4 to 5 days and let them sit at room temperature for about 15 minutes to soften before you eat. They can also be frozen. Happy baking!