This Thermomix Boston Bun recipe is simple to make and just delicious!

Enjoying a slice of freshly baked Boston Bun brings up some pretty special memories for me, my Great Nan used to buy one of these from the bakery every time she visited as it was also her favourite sweet treat. Whenever we are back in Victoria I always stop at the same bakery to buy one and they are JUST like I remembered.
I'm really not sure why I've never tried to make a Boston Bun before, I think I just put it into the too hard basket and was worried I wouldn't be able to pull off a version like the one I grew up with - I really had nothing to worry about though! I promise you that this recipe is REALLY easy to put together and is certainly not as fiddly to make as I thought it may have been.
It wasn't until I started looking at recipes that I discovered mashed potato is one of the main ingredients - I honestly had no idea and you would not know at all that it was in there unless someone told you.
All up this recipe will take a good hour and half to make (that includes baking time) and you then need to let your bun cool completely before adding the icing - it's certainly worth the wait though!
Tips for Making our Thermomix Boston Bun Recipe:
- You can use leftover mashed potato if you wish. I would suggest warming it up first to help the sugar dissolve.
- I used a 20cm cake tin to bake my Boston Bun, you can use a smaller or larger tin if you wish however the cooking time will vary.
- You can also choose to cook this on a baking tray lined with baking paper if you prefer.
- I used a combination of sultanas and raisins for this recipe, you can use any type or combination of dried fruit that you wish.
- This Boston Bun is best stored in an airtight container at room temperature for up to 3 days. It's also freezer friendly either iced or plain.
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Thermomix Boston Bun Recipe
Equipment
- 20cm Cake Tin
- Thermomix
- Oven
Ingredients
- 250 grams peeled potatoes chopped into 3cm pieces see notes
- 220 grams caster sugar
- 300 grams self raising flour + extra for dusting
- 1 teaspoon cinnamon
- 1 teaspoon mixed spice
- 80 grams sultanas
- 50 grams raisins
- 230 grams milk
- 2 tablespoon desiccated coconut
Icing
- 300 grams soft icing sugar mixture
- 30 grams butter at room temperature
- 2 tbsp milk
- 1 teaspoon vanilla extract
- ¼ cup desiccated coconut to decorate
Instructions
- Line the base and sides of a 20 cm round cake tin with baking paper and lightly grease. Set aside until needed.
- Add 1000 grams of water to your Thermomix bowl and place the chopped potatoes into the basket. Add the lid and cook for 14 minutes, varoma temperture, speed 2. Check the potatoes with a knife to see if they are cooked through.
- Pre-heat your oven to 200 degrees.
- Carefully remove the basket from your Thermomix bowl and drain the water.
- Place the butterfly attachment in the bowl (carefully as the bowl will still be hot after cooking the potatoes) and return the potatoes to the bowl and add the caster sugar. Mix for 10 seconds, speed 4 to combine. If needed, mix for a further 5 seconds, speed 4 or until smooth.
- Add the self raising flour, cinnamon, mixed spice, milk and coconut and mix for 10 seconds, speed 4.
- Add the sultanas and raisins and select the kneading function and mix for 40 seconds.
- Pour the mixture into your prepared cake tin and gently smooth the surface with a metal spoon/knife.
- Place the Boston Bun into your pre-heated oven and bake for 35 - 40 minutes or until cooked through when tested with a skewer.
- Remove the cooked bun from your oven and allow to cool for 15 minutes before carefully removing from the tin and placing onto a wire rack to allow to cool completely.
- Once the bun has cooled, combine the icing ingredients in a small bowl and mix until smooth. You want your mixture to be stiff enough so that you can spread it onto the bun and it won't run down the sides.
- Add the icing and sprinkle the coconut over the top.
Notes
- You can use leftover mashed potato if you wish. I would suggest warming it up first to help the sugar dissolve.
- I used a 20cm cake tin to bake my Boston Bun, you can use a smaller or larger tin if you wish however the cooking time will vary.
- You can also choose to cook this on a baking tray lined with baking paper if you prefer.
- I used a combination of sultanas and raisins for this recipe, you can use any type or combination of dried fruit that you wish.
- This Boston Bun is best stored in an airtight container at room temperature for up to 3 days. It's also freezer friendly either iced or plain.
Nutrition
Enjoy!
Amber Hill says
I assume you have to remove the butterfly??? At what stage???