Melt ‘n’ Mix Chocolate Mud Cake

This cake works for almost any occasion — birthdays, dinner parties, rainy afternoons, or even just because you need a chocolate fix (which, let’s be honest, happens often enough). It’s deeply chocolatey without being too sweet, holds up beautifully if you make it a day ahead, and freezes like a dream if you want to squirrel away a few slices for later.

Melt ‘n’ mix chocolate cake has been part of our family for over 20 years. My mum first found the original version on taste.com.au (though it’s not there anymore), and it’s been baked countless times since. I’ve tweaked it quite a bit over the years, but the heart of it remains the same: it’s rich, easy, and so forgiving.

I honestly can’t tell you how many times we’ve made this cake. My mum always makes the raspberry version for my brother’s birthday every single year. I pull it out anytime I need something chocolatey that feels a little bit special but doesn’t ask much from me. No fancy mixers, no frosting, no complicated layers — just one bowl, a wooden spoon, and a few simple steps.

What makes this cake extra special is the gooey chocolate layer in the middle. As it bakes, the chunks melt into a soft centre that feels like you’ve hidden a ganache layer inside. The next day, it firms up into a truffle-like centre that slices cleanly but still feels rich and soft.

Ingredient Notes

Unsalted butter: The rich, fudgy foundation. Using unsalted lets you control the salt levels yourself.

Dark chocolate: The star ingredient. I always say: use chocolate you’d happily eat on its own. So basically any chocolate. A good 70% dark chocolate gives you the richest flavour. The 200g melts into the batter, while the extra 100g creates that gooey centre.

Coffee or water: Coffee acts like a flavour amplifier for chocolate without making the cake taste like coffee. Vanilla also enhances the flavour of chocolate, so sometimes I will add another teaspoon of vanilla if I cant be bothered making as espresso shot.

Caster sugar: Finer than regular granulated sugar, so it dissolves smoothly into the warm mixture.

Eggs: Give the cake structure and that dense, fudgy crumb.

Plain flour, cocoa powder, baking powder & salt: These balance out all the richness. The cocoa deepens the chocolate flavour, the baking powder gives it a gentle lift, and the salt keeps it from tipping into overly sweet territory.

Icing sugar: For that final, simple finish. It dresses the cake up without fuss.

Method

Prep your tin: Preheat the oven to 170°C conventional or 160°C (fan-forced) and line a 20cm (8-inch) round cake tin with baking paper.

Melt the base: In a microwave-safe bowl or double boiler, gently melt together the butter, 200g of chocolate, and the coffee or water. Stir until smooth, then let it cool for 2 minutes. If I’m doing it in the microwave, I like to do it in 30 second bursts, stirring in between each burst.

Sweeten and enrich: Add the caster sugar to the melted mixture and stir well. Then mix in the vanilla and beat in the eggs until the batter is glossy and well combined.

Finish the batter: Sift in the flour, cocoa powder, baking powder, and salt. Stir until just combined and smooth. Don’t overmix — you want the batter to stay tender.

To finish: Once the cake is completely cool (or just before serving), dust the top with icing sugar.

Variations

Raspberry middle: Add 1 cup of fresh (roughly a punnet) or frozen raspberries on top of the chocolate layer before the second pour of batter. The tart raspberries cut through the rich chocolate beautifully.

Caramello centre: Replace the middle chocolate with chunks of Caramello or another flavoured chocolate for a gooey, sweet surprise — my kids love when I use white chocolate.

Nutty twist: Mix in 1/3 cup of chopped walnuts or hazelnuts to the batter before baking. Blobs of hazelnut spread in the middle make it even more decadent.

Peppermint version: Use peppermint dark chocolate for the middle layer for a festive twist.

Orange twist: Stir some finely grated orange zest into the batter for a subtle citrus note. You could use orange-flavoured chocolate in the centre for a jaffa like cake.

Serving & Storage Notes

Best eaten the next day: Letting the cake rest overnight transforms the texture. The middle solidifies slightly into a rich, truffle-like layer, and the rest of the cake becomes dense and mudcake-y. It slices beautifully and the flavours deepen, making it ideal for a make-ahead dessert. Or breakfast. No judgement here.

Same-day magic: No time to wait? No problem. After baking, let the cake sit for at least 30 minutes. Serve it warm with a scoop of vanilla ice cream and you’ll get a gooey centre that’s rich and soft—almost like a molten pudding.

Storage: Keeps well for 3–4 days (assuming it lasts that long) in an airtight container at room temperature. Freezes nicely too; if you pre-slice there’s always a quick dessert on hand.

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Extra Serving Ideas

• Serve with whipped cream or fresh berries for a lighter finish.
• Drizzle with warm ganache or salted caramel sauce for full indulgence.
• Dust with cocoa powder instead of icing sugar for a deeper chocolate hit.
• Warm slices briefly in the microwave to recreate that molten centre.
• Pair with espresso for a grown-up dessert moment.

Pro Tips

• Don’t skip the cooling step after melting your butter and chocolate; it helps prevent scrambling the eggs.
• Always sift the dry ingredients — it keeps the batter smooth and lump-free.
• Use room temperature eggs for better incorporation.
• If you’re nervous about overbaking, start checking the cake at 50 minutes. You want moist crumbs on the skewer.

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Quick FAQ

Can I make this gluten-free? Yes! Swap the plain flour for a good 1:1 gluten-free baking blend. This recipe works amazing with almond meal/ ground almonds, you will need to use 1 1/4c of almond meal and cook for 60mins.

Do I have to use coffee? No. Water works fine or add a little extra vanilla.

What kind of chocolate works best? Use dark chocolate you enjoy eating. You can easily switch it for a mix of dark and milk, or flavoured chocolate depending on your taste.

Can I freeze it? Yes. Slice, wrap, and freeze for up to 3 months. Defrost slices at room temp or warm gently in the microwave.

Can I double it? Yes, but bake it in two tins for best results. The centre can struggle to set properly if baked too deep, or bake in a 30cm tin, this works too.

Can I make this in a muffin tin? Yes! I like to a half and half flavouring with the middle chocolate layer. Last time I tried white chocolate raspberry and peanut butter chocolate. It makes 12 muffins, I recommend using muffin liners as it is a bit of a gooey one. You will need to reduce the cooking time to about 20-25 mins as well.