This rich chocolate mashed potato cake with tahini drizzle is a perfect for any celebration. The mashed potato brings bulk to the cake with less fat and sugar.
I have an announcement (sounds klaxon)! In June I’ll be teaching a class about vegetable cakes at the renowned vegetarian cookery school, Demuth’s in Bath. I’m so excited! It’s such an amazing place and I’m so unbelievably flattered that they’ve asked me. Please come along if you can. We’ll bake cakes. We’ll talk about veg. We’ll experiment. My hands might shake a little with nerves, but hey, that’s useful during whisking, right?
I’ve never done anything like this before, so it will be a wonderful challenge. Life can be so busy that I don’t think I challenge myself enough. My sister jumps out of planes, kayaks with whales and flies a teeny tiny little plane in the air even though it could fall out of the sky. My other sister is a 5’2″ ninja who is so highly trained in self defence that she could basically stop a gang of thugs with her pinky finger and an air kiss.
I bake cakes. Sure, there’s a challenge in getting the maximum kale into a kale cupcake without it tasting of lawn, but my comfort zone might just be a little too snuggly and warm these days. So I’ll teach a class about cake. Cake with vegetables. Lots of vegetables. Because after a few years now of baking with veg, you could call me an expert. I’ve sussed out the ratios so the desserts never taste of veggies. I’ve experimented with flavours, textures, methods. I’m that woman who bakes with veg. Join me, it will be great fun.
Potato in cake? Yup. Potato has been used in cake for hundreds of years. It adds bulk and moisture, plus helps the cake to keep for longer. You can’t taste the potato, but it adds a nice extra richness to this decadent chocolate cake. I love tahini, so I’ve added an extra dash of flavour by drizzling it over the cake. This is a celebration cake, a celebration of cake. Let’s party.
Get the recipe for my Mashed Potato Cake with Tahini Icing
- 225g (1 cup) butter
- 345g (1 ½ cups) granulated sugar
- 2 eggs
- 2 teaspoons vanilla extract
- 200g (1 cup) mashed potato, cooled (no milk or seasoning added)
- 250g (2 cups) plain (all-purpose) flour
- 75g cocoa powder
- 2 teaspoons baking powder
- ¼ teaspoon salt
- ¾ cup buttermilk (or cow’s milk with 1 teaspoon of lemon juice stirred in)
- 85g (3/4 cup) plain chocolate, broken into pieces
- 100g unsalted butter, softened
- 200g powdered icing sugar, sifted
- 1 teaspoon vanilla extract
- ½ cup tahini
- 1 cup powdered icing sugar
- Preheat the oven to 175C/350F. Grease and line 2x9” round cake tins
- Cream the butter and sugar together in a large bowl until light and fluffy. Add the eggs, one at a time and beating each one in well. Stir in the mashed potato and vanilla.
- In a separate bowl, whisk the flour, cocoa, baking powder and salt. Alternating, add ⅓ of the flour to the egg mixture and gently combine, then ⅓ of the buttermilk mixture. Repeat until all combined.
- Pour the mixture into the prepared tins and bake for 35 minutes or until an inserted skewer comes out clean. Cool for 10 minutes in the tins and then turn out onto a wire rack to cool completely before icing.
- For the Chocolate Frosting:
- Melt the chocolate in a microwave or in a bowl over a pot of simmering water (but not touching the water). Allow the chocolate to cool slightly.
- In a large bowl, beat the butter until soft and fluffy. Beat in the powdered sugar, a little at a time. Beat in the vanilla and then gently stir in the melted chocolate. Store in the fridge until ready to use. If too thick, add a teaspoon of milk to loosen. Frost completely cooled cake as desired.
- For the Tahini Drizzle:
- Mix the tahini and icing sugar together until thick but still runny. Drizzle over the frosted cake.
What’s been happening this week?
* I was interviewed in The Sunday Telegraph.
* I had two recipes in Cosmopolitan featuring my cauliflower and almond churros and kale and apple cake.
* We’re completely renovating our new house. The wonky Victorian walls are proving difficult and my husband badly hurt his hand, but on the upside, we’ve turned a random cupboard-like room into a library. I love it. Love it love it. Only my husband has now put a record player in it and is trying to claim it as his own space. I’m going to put a lock on it to keep him out.
PIN FOR LATER!
Michael Allen
Hi,
I came across your recipe while looking for an unusual cake to make and am going to give it a try tomorrow! Just one question though. I see the mash is made without milk , but does it still need butter or is it just purely potato?
Thanks again for the recipe!!
Kate Hackworthy
Hi Michael, just potato is best, but if you have leftover mash that has butter, it should still be fine. I hope you like it!
Michael Allen
Thanks for the quick response! I’ll let you know how it went 😉
Charlotte
Can confirm that this cake tastes AMAZING! I made it and brought it into work. My colleagues couldn’t believe I used mashed potato. The best secret ingredient and this will be the only type of chocolate cake I’ll be making in future 🙂
Kate Hackworthy
I’m sooooo pleased that you liked it!! Keep an eye on the blog as I’m testing recipes for white chocolate and purple potato cupcakes 🙂
Best Cake Mixers
Yummy!!!! This is really delicious
plasterer bristol
this sounds good. Something new to try as well. thanks for sharing this recipe.
Simon
cookwitch1
I think I might be obsessed with your site. I’ve got two weekends to myself coming up, and I foresee some baking.
I wanted to share this recipe, because I loved the colour so much. (You can also now buy purple yam puree in Chinese grocers, so…)
http://cookwitch.blogspot.co.uk/2010/12/slocombes.html
Maria
How many servings should this make?
Fiver Feeds
Didn’t know this about the potato in cake, interesting fact 🙂
Hannah | The Swirling Spoon
I adore this cake and everything about your website. All your recipes are brilliantly unique!
Good luck with the cake class 🙂
Kate Hackworthy
THanks so much, Hannah! 😀
karen278
LOVE this cake Kate and also your stunning photos too! I must book a course at Demuths now that you are there too! Karen
Kate Hackworthy
Thanks so much, Karen. I’d love to see you at Demuth’s!
kellie anderson
I love this idea so much; I wish I could whip it up right now! Genius, gorgeous loveliness. And many congratulations on your cooking class at Demuth’s. I can imagine that it will sell out quickly, especially if the clientele get wind of this corker of a recipe.
rovinglights
Wow! This looks amazing! Tahini with anything and everything 🙂 Best of luck with the course and have fun. If only I was around Bath I would love to join 🙁
Akina Era
this is so cool! i’ve tried potato bread before but never in cake. i’m sure it tastes just as wonderful as it looks. thanks for sharing, i will give veggies in cake a shot sometime!
Kate Hackworthy
I hope you enjoy your adventures in vegetable cakes!
recipesfromapantry
You had e at mashed potato with chocolate. Wow. Plus all you sisters seem rather amazing.
Kate Hackworthy
My sisters definitely are amazing. I miss them very much (they’re on the other side of the planet).
Elizabeth
Congratulations on the teaching job – how exciting! 🙂 I love each and every one of your recipes; you are such an inspiring blogger and this one is no exception – gorgeous!! (your comment about kale cupcakes tasting like lawn made me lol, for real!) 😀 Thanks for sharing with the #nowastefoodchallenge!
Kate Hackworthy
Exciting but definitely scary, Elizabeth! Thanks for your lovely, kind words 😀
Thalia @ butter and brioche
Wow! Mashed potato in a cake? You definitely have got me curious to know what this tastes like. Looks incredible though & I would love to learn more about how to use veggies in desserts.
Kate Hackworthy
You can’t taste the mashed potato at all!
peter @feedyoursoultoo
Gorgeous. I cannot believe the ingredients you used.
Kate Hackworthy
Thanks so much, Peter!
Cindy @ Hun... What's for Dinner?
I can just imagine how moist the mashed potatoes make this cake. Brilliant!
Kate Hackworthy
It really did make it nice and moist, Cindy!
Joana
Quite happy to have found your blog. Wonderful recipes and a mutual love for natural baking 🙂 will be following 😀
Kate Hackworthy
That’s lovely Joana :). Natural baking is the best!
Keep Calm and Fanny On
You will be FABULOUS, I have no doubt! What fun! I’ve always wanted to do a course there, maybe this’ll be the one! Fanny had a potato chocolate pudding… She could’ve done with your help, it was like eating mashed potato with hot chocolate sauce! So thrilled for you, I’m sure first of many exciting adventures to come…
Kate Hackworthy
Thanks Fanny, you’re always so supportive. I would love to see you there 🙂
Fuss Free Helen
Just gorgeous Kate! What a beautiful cake, I love the tahini drizzle
Kate Hackworthy
Thanks Helen. The tahini drizzle was pretty lush. 🙂
Jac -Tinned Tomatoes (@tinnedtoms)
We love using up mashed potato here is Scotland Katherine. It tops pies, i made into tattie scones and we make it into a sweet coconutty delicacy macaroons, not to be confused with macarons. I love the sound and look of your cake. Congrat on the new job, you’ll be great!
Kate Hackworthy
I sooooo want to try potato macaroons!
superfitbabe
Oooh, I’m going to add sweet potatoes in mine!
Kate Hackworthy
That would be amazing!