Marshmallow Chocolate Cupcakes

Janine Ogden
Nov 2, 2024
3 min read

Introducing my perfect moist chocolate sponge recipe. Don't be concerned about how runny the batter is - it bakes into a rich and tender crumb that will fast become your favourite.

You'll need to give yourself a little extra time because the cocoa powder is melted into boiling water, but needs to cool to room temperature before adding to the batter.

Marshmallow Chocolate Cupcakes

Makes 12

Prep 45 mins plus cooling

Ingredients:

For the sponge:

50g cocoa powder
200ml boiling water
120g butter - baking spread will work, but your bake will be a bit more crumbly
180g sugar - light brown soft gives a fudgier texture, and caster and golden caster both work very well
2 large eggs
180g self raising flour

For the marshmallow buttercream:

200g butter, very soft - heat it gently until it's just starting to go liquid. You can use a baking block if you are happy with the flavour & texture. but nothing from a tub, because it's not firm enough at room temperature
400g icing sugar
1 tsp vanilla extract
Half of a 213g jar marshmallow fluff - Sainsbury's stock it for £2.20 at the time of writing this

For the filling & topping:

The rest of that jar of marshmallow fluff
Mini marshmallows
Some sort of crushed biscuit - Biscoff goes really well, or digestives

Method:

Add the boiling water to the cocoa, and stir until melted. Put aside to cool to room temperature.
Make sure your oven rack is in the centre of the oven, and preheat to 140C/285F if you have a fan oven, 160C/320F if not a fan oven, or gas mark 3.
Line a muffin tray with 12 muffin sized liners.
In a large bowl, cream together the butter and sugar. Add the eggs one at a time and beat with an electric whisk until well blended.
Sift half of the flour into the bowl, and add half of the cooled cocoa. Mix with a hand whisk.
Add the rest of the flour and cooled cocoa and whisk again - don't overmix.
Put the batter into a jug - use a silicon spatula to scrape the bowl. Using a dessert spoon for control, pour the batter between the 12 muffin liners.
Bake for approx. 25 minutes until they are well risen. Ovens can vary, so keep an eye on them - don't open the oven door too early or they'll sink in the middle. Put your ear close to the tray (please be careful!) - if you can hear them 'singing' they're not fully baked yet.
Remove from the tray as soon as they're cool enough to handle without burning your fingers - this should prevent peeling cases. Cool on a wire rack.

Meanwhile, make your buttercream:

Stir the vanilla extract into the very soft butter.
Sift the icing sugar to remove lumps, and mix into the butter. You can use a wooden spoon, silicon spatula, electric whisk, or the beater attachment of a stand mixer. Just be aware that if you use a whisk you may get air bubbles in your buttercream, but that's really not a big deal.
Leave your buttercream to stand for 5-10 mins so the sugar particles can dissolve into the butter. Using this method saves having to mix for a long time. Add a small splash of boiling water straight from the kettle, mix it in, and using a silicon spatula, paddle back & forth against the side of the bowl to smooth the buttercream.
Stir in half the jar of marshmallow fluff.

Once your cupcakes are completely cool:

Use an apple corer to cut the centres out and fill with the remaining marshmallow fluff.
Put the piping tip of your choice into a piping bag, fill the bag with buttercream (don't forget to burp it!) and twist or tie the top of the bag, so the icing doesn't escape.
Pipe the buttercream onto the cupcakes - there are hundreds of YouTube videos showing different techniques. You can also spread it on with a palette knife for a more rustic, homemade effect like in the pic.
While the icing is still soft, decorate with the mini marshmallows and biscuit crumb.
If you have a cook's blowtorch, use it to carefully toast the marshmallows, taking care not to melt the buttercream.