How To Make A Volcano Cake (And Watch It Erupt!)

You can decorate your volcano cake with chocolate icing and use a piping bag to create a good effect.

Whether you're hosting a Jurassic Park themed birthday party or want to impress your little guests, easy cake recipes for kids don't come much cooler than this volcano cake.

While baking powder or baking soda mixed with vinegar will create a fantastic eruption they don't really add much to the flavour of your cake. Luckily there is an alternative volcano cake recipe that tastes as good as it looks.

This recipe is something of a show stopper and surprisingly it's easy to make and doesn't require any fancy cake pans to be bought. The secret is in the hidden bottle at the centre which you use to create your eruption. You won't even need to bake this recipe as a trial run, you can simply try out the Coca-Cola and Mentos combination in a bottle to check how well it works. When you're confident of the amounts you'll use you can tailor the recipe to create the right size cake. We've gone for a basic vanilla sponge recipe but it will work equally as well with chocolate sponge recipes.

If this bake isn't hitting the mark with fussy kids why not try other recipes? How about a football cake for teens or a Mickey Mouse one for Disney-fans?

You can get your kids to help you prepare the ingredient or put the decorations on the cake.


For The Cake: 300g softened butter, 300g caster sugar, six large eggs, 300g self raising flour, two tablespoons of milk, red paste food colouring.

For the Topping: 500g marzipan, 200g dark chocolate, 250g chocolate sweets for decoration, 400g red buttercream.

For The Lava: Large bottle of Coca-Cola, pack of fruit Mentos, red food colouring.

Equipment: Small empty soft drinks bottle, cake board, sparklers, 18cm round cake tin, 800-900ml oven proof bowl.

A volcano cake is simple to make with this recipe and kids will love the chocolate eruption.


1) Preheat your oven to 180c/160c fan/gas mark 4. Grease and line your tin and the oven-proof bowl.

2) Mix together the butter, sugar, eggs, flour and milk in a mixing bowl until you have a light and creamy consistency.

3) Place around 450ml of this mix into your prepared tin in heaped spoonfuls.

4) Take another 450ml of this mix and add the red food colouring and stir well. Using around a third of the red mixture dot it into the tin amongst the white cake mix. Use the end of a spoon to swirl the colours together.

5) Now place the remaining red and white batter into the oven-proof bowl and swirl with a spoon end to marble it.

6) Place the cakes in the oven. The bowl cake should take around 40-45minutes and the cake tin around 30-40 minutes. Check the cakes are baked by inserting a skewer and ensuring it comes out clean. Remove and set to one side to cool.

7) Use a sharp knife to carefully cut out a hole from the cake in the tin which is big enough to fit the small drinks bottle. Slice the bowl cake in half horizontally and cut a shape out for the bottle in both pieces. Set the off cuts to one side.

8) Place your round cake on a board. Spread the buttercream on top and then add the larger half of the bowl cake so the holes line up. Spread with more buttercream then add the final sponge to the top to form the ridge of the homemade volcano. Carefully insert your small bottle without the lid.

9) Using the buttercream and the sponge off cuts build up your shape to hide the water bottle, but do ensure you can still access the top of it. Cover the volcano cakes with the buttercream.

10) Roll out the marzipan to a large circle shape, big enough to cover the whole cake. Carefully lift on and drape it roughly. It doesn't need to look perfect as this will help mimic the random shapes of volcanoes.

11) Melt the chocolate and use a pastry brush to paint on the melted chocolate. Add the chocolate sweets to give the finished bake a rocky appearance and continue to cover with the chocolate.

12) For the explosion mix together 350ml of Coca-Cola and add a dash of red food colouring. Use a funnel to pour into the hidden bottle. To start the explosion and get the lava to flow make a paper tube and inset to the top of the bottle. Drop in the five Mentos in one go for a fantastic exploding cake effect!

The kids will be amazed at this volcano cake which actually erupts and parents love how easy it is.

Tips And Alternatives

While fruit Mentos are suitable for those who are vegetarian, gluten-free or have a nut allergy they're not suitable for vegans.

For very young kids you could skip the eruption part and instead create a volcano cake topper of lava. Follow the recipe above but there's no need to cut out a hole for a hidden bottle. Instead carve away a little of the mound of your cake to create a crater and push in red lace sweets and let them fall down the bake.

As with other recipes you can easily switch up the ingredients for gluten-friendly versions.

A volcano cake is very simple and impressive and everyone will enjoy it.

Good To Know

Why not add cake sparklers or fountains for an extra fiery effect? You will need an extra pair of responsible hands to co-ordinate lighting candles and dropping in Mentos, so make sure to have an adult with you to do these more dangerous jobs.

While little hands can definitely have fun helping you make this chocolate volcano recipe, it's best to leave the final step to the grown ups and ask kids to stand back while it's in full eruption mode.

This recipe can be made a day in advance but do bear in mind you'll need a big enough cake box to store it at room temperature in. Don't add the Coca-Cola to the bottle until right before you want it to explode so no fizz is lost.

This cake should serve around 12-15 guests. Any left over cake can be double wrapped in foil and cling film and then frozen where it will keep for up to two months.



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