Coffee Mug Cake with Marshmallow Fondant

“A birthday is not a birthday unless you have a cake”, according to my kids. With my dads birthday looming they were asking what kind of a cake I was going to make. I won’t even go into what they suggested, lol! I did a search on line for mens cakes. Most of the results came back with cakes that looked liked beer mugs. My dad is not a beer drinker, but he loves his coffee, every opportunity he is off finding cafes to indulge in his passion. So a cake that hopefully looks like a coffee mug was the plan! Unfortunately the fondant turned out a bit wonky, will teach me for doing it at 10pm at night when I am tired! Sad excuse I know, isn’t that when all mums are working on cakes…  My dad’s response to the cake when he saw it was priceless, and made it all worthwhile! 

In order to get the height for the cake, I decided to make layers. Normally I would make a normal sized cake and cut it across through the middle to get the different layers, but I wanted to make it in my small round tin (18cm) to make it look more like a mug, so each layer was baked individually. I used two different cake recipes, mainly since I had made custard tarts that morning for a school event and had 5 egg whites waiting to be used and I find the egg white cake perfect for using them up. I have had this recipe saved on my laptop for a while, and unfortunately can’t remember where it comes from. I have included my thermomix directions and the traditional. I used Marshmallow fondant for the mug and carob butter icing for the coffee look on top.

For the second layer I used the too easy chocolate cake from the Thermomix EDC (page 129) and used brown sugar instead of coco or carob. If you don’t have a Thermomix, you could just use your favourite cake recipe or my Caramel Mud Cake Recipe. This recipe would also make enough layers if you wanted to use this recipe for all of them.

I seperated each layer with custard. I would have added coffee to the custard, but since my kids were having it too I thought better, and although decafe is suitable for the failsafe diet, I didn’t have any, so I just went for carob custard.


Egg White Cake

6 large egg whites
250 g caster sugar
160 g plain flour
1 heaped Tbsp cornflour
1 tsp baking powder
100 g melted nuttelex, cooled
1 tbsp vanilla essence

Preheat oven to 180°C

Thermomix Directions:
If you are making your own caster sugar, mill white sugar for 3 seconds on speed 9. Set aside.
Insert the butterfly into the Thermomix bowl. Whisk the egg whites with 2 tablespoons of the sugar on speed 4 for 1:30 minutes, Whisk until white and foamy.
Add flour, cornflour, the rest of the sugar and baking powder. Mix on Speed 2 for 10 sec. Add melted nuttelex and vanilla. Mix on speed 2 for 10 sec.
Pour the mixture into greased cake tin and bake for 30 – 40 minutes. Test with a skewer or toothpick to ensure it is cooked. Allow to cool slightly before turning out.

Traditional Directions:
Whisk the egg whites with 2 Tbsp of sugar until thick, white and foamy. Mix the rest of the sugar with flour, cornflour and baking powder, then sift into the egg mixture and fold in gently. Finally fold in cool melted butter and vanilla.
Pour the batter into a buttered bundt cake tin and bake in a pre-heated 180 C oven for 30-40 minutes. Test with a skewer or toothpick to ensure it is cooked. Cool slightly before turning out of the cake tin.

Notes: I used a small 18cm tin for the cake and I halved the mixture and baked each layer separately in the oven.


Carob Custard

50g carob buttons
90g sugar
2 eggs
500g milk
40g cornflour

Place carob buttons and sugar into TM bowl. Pulverise for 20 seconds on speed 9. Add remaining ingredients, cook for 7 minutes at 90°C on speed 4. Transfer to a another bowl and keep in the fridge until ready to assemble cake.

Notes: If you don’t have carob buttons, you can use 40g carob powder, just add it with the remaining ingredients after pulverising the sugar.


Carob Butter Icing:

125g sugar
30g Carob buttons or powder
50g butter

1 teaspoon milk

Add sugar and carob buttons to the Thermomix bowl, pulverise for 1 minute on speed 10. (If using carob powder, add with the butter). Add butter and milk and mix on speed 4 for 20 seconds or until combined. This recipe can be easily doubled if making a larger cake.


Marshmallow Fondant Icing

600g sugar (use icing sugar for traditional directions)
225g marshmallows
1 ½ tablespoons water
Extra icing sugar for rolling 

Thermomix Directions:

Place sugar in the TM bowl, grind 2-3 min speed 10, set aside.

Place marshmallow and water in the TM bowl. For 2 minutes at 60 Degrees on speed 3. Add icing sugar, mix 1 min on interval.

Place gladwrap into a small bowl and sprinkle it lightly with icing sugar.  Remove the fondant  immediately from TM bowl. And pour into the prepared bowl sealing it up in the gladwrap for storage. Allow to rest for at least a few hours or over night before use.

Traditional Directions:

Place marshmallows and water into a microwave bowl. Microwave on high for 30 seconds. Stir well, if necessary, microwave for another 30 seconds until completely melted. Add icing sugar to the melted marshmallows and mix until combined. Place gladwrap into a small bowl and sprinkle it lightly with icing sugar. Pour into the prepared bowl sealing it up in the gladwrap for storage. Allow to rest for at least a few hours or over night before use.

Kneading the fondant

To roll the fondant:

Sprinkle icing sugar onto a prepared work surface and onto your hands. Knead the icing like dough, adding more sugar until it is no longer sticky. Be careful not to add too much or it will become stiff and hard to work with. Once it becomes smooth, it is ready to roll. Keep sealed in glad wrap or a container when not working with it.

If adding colour, (I use hoppers colours from Allergy Train as they are coloured by fruit and vegetables and not numbers), break off a section of fondant (the amount you think you will need) make a hole with your finger and add a few drops of colour. Knead until all the colour in evenly mixed. Add more if you need a deeper colour.

If the icing gets too hard to work with, placing in the microwave for 10 seconds can help it to be a bit more pliable. When ready to roll the icing, pour a small amount of oil on your hands and spread lightly over the work surface to stop the fondant from sticking.

Notes:  There are lots of video tutorials on line if you do a search and here is a link to  What’s Cooking America, this is the page I used to learn the technique of preparing and rolling the fondant and she explains it so much better than I ever could. It is an american link and she uses shortening, I just use vegetable oil.


To Assemble the Coffee Mug Cake:

Place a small amount of butter icing on the middle of the plate you are using to stop the cake from slipping. Place the first layer of egg white cake on the plate. Spread a layer of carob custard over the top. Next I put the cake layer using the recipe “Too Easy Chocolate Cake” from the Thermomix EDC. Spread another layer of custard. Make the third layer with the egg white cake.
Ice the whole cake with the butter icing. Place into the fridge until ready to place the fondant on.

Roll the fondant into a strip that will measure the size of your cake and wrap around the cake, smoothing it around as you go. To make the handle, bend a straw and wrap a small amount of fondant around it leaving about 1 cm free at both ends. Bend into the shape desired and poke the ends if the straw into the cake. Smooth the handle edges down against the cake. I placed a small container against the handle to hold it in place while it set in the fridge over night.

I drew a design on an A4 piece of paper similar to what the coffee shops use. Then cut it out with a craft knife. I slightly moistened the carob icing so the paper would stick, then sprinkled icing sugar over the cut out. Lift it off carefully to not disturb the icing sugar pattern.






  1. Oscar's Mum says

    You are so clever Rona, it looks great. If Oscar saw that he would ask for a Baby Chino cake!

  2. Darren Burns says

    Pretty Spectacular Sis!!! Wish we could have been there to sample.

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