Learn how to make this gluten-free lemon cake recipe from plain mashed potatoes, ground almonds, and sorghum flour. The cooled cake is topped with homemade lemon curd and fresh raspberries for a festive cake that celebrates spring and summer.
My favourite cake combination might be cake with lemon curd and berries. It's not hard to make the components, and I've learned over the years that it's best kept simple: a single cake layer topped with a thick layer of lemon curd and a scattering of berries. And you can serve this with more lemon curd on the side for those who can't get enough of it, which is basically everyone.
I urge you to make your own lemon curd because the stuff in the jars just isn't right. In fact, the jarred commercial lemon curds are downright awful if you ask me. They taste artificial and they are often an odd translucent fluorescent yellow colour. Homemade is best in this case!
Special equipment
This cake is impressive because of its height. I baked it in a tall 8-inch springform pan, but you can also put it in a regular 9-inch cake pan and it will work just as well, if not better. The baking is a little faster in a 9-inch cake pan, (taking about 45–50 minutes, instead of over an hour).
To bake this cake, use an 8-inch springform pan and take the time to properly prepare the springform pan for baking. Butter the pan all over and dust it with flour. Line the bottom with parchment paper so that you can get the cake off the springform bottom easily.
I do not lead a gluten-free lifestyle, but I find it interesting to bake gluten-free. If nothing else, it's a challenge, and I think baking with different flours and starch sources is really exciting.
I've baked with chestnut flour to make gluten-free cranberry chestnut financiers, rice flour to make gluten-free pistachio financiers, and a combination of gluten-free whole grain flours to make this gluten-free raspberry cake.
This gluten-free cake has the look of a good cake, the crumb of a good cake, and an impressive mouthfeel. It contains a lot of ground almonds so there is an almond flavour in it that is the perfect setting for a generous layer of lemon curd, and it's made with mashed potatoes (from yellow boiling potatoes). And there's no xanthan gum, which is a bonus for me. For now, I'm sharing with you this recipe, but if you the process for developing a gluten-free cake, you can find the process of how I got to this final recipe for a gluten-free mashed potato cake.
Gluten-free lemon cake with raspberries
Ingredients
Lemon curd ingredients
- 100 g granulated sugar, ½ cup
- 84 mL fresh lemon juice, freshly squeezed
- 4 large egg yolk(s)
- 72 g unsalted butter, ~⅓ cup, cut into pieces
Gluten-free lemon cake ingredients
- 150 grams unsalted butter, ½ cup + 2 tbsp
- 200 grams granulated sugar, 1 cup
- 3 lemons, zested
- 4 large egg(s)
- 1 teaspoon pure vanilla extract
- 175 g ground almonds, 1 ½ cups
- 75 g sorghum flour
- 250 g mashed potato, 1 cup, packed, from about 400 g yellow potatoes that were peeled, boiled, passed through a ricer and then cooled to room temperature
- 2 teaspoon baking powder
Garnish
- 2 pints fresh raspberries
Instructions
For the lemon curd
- Have a bowl ready with a strainer over top to strain the curd right away at the end of this recipe.
- Combine half the sugar with the lemon juice in a saucepan. Begin to heat it on medium–high heat.
- Meanwhile, beat the yolks with the rest of the sugar til they have lightened in colour.
- When the lemon juice is steamy and just about boiling, dump it onto the light yolk mixture, and whisk to combine to temper the eggs.
- Pour the lemon egg mixture into the saucepan and continue heating, whisking constantly, until it comes to a boil. Boil for 1 minute, whisking non-stop.
- Turn the heat off, and add the butter a piece at a time while still whisking.
- When all the butter is added, strain the mixture into the prepared bowl. Cover with cling film so that it touches the entire surface of the curd.
- Refrigerate overnight.
To make the cake
- Preheat the oven to 350ºF. Butter and flour (I used millet flour) an 8-inch springform pan, then line the bottom with a round of parchment. Set aside.
- In the bowl of an electric mixer fitted with the paddle attachment, cream the butter and the sugar with the lemon zest until it is light and fluffy,
- Add the eggs, one at a time, scraping down the sides of the bowl as needed and beating well between each addition.
- Add the vanilla and the ground almonds and beat the mixture again, scraping down as needed.
- Add the sorghum flour, beat again, then finish the cake batter by adding the mashed potatoes and baking powder. Continue mixing in the stand mixer until the batter is well mixed.
- Pour the cake batter into the prepared pan and bake for about 65 minutes until the cake feels firm and a cake tester inserted into the middle comes out clean.
- Let cool 10 minutes before unmolding onto a wire rack to cool completely.
To assemble the cake
- Peel off the parchment lining from the cake and set it on a cake stand.
- Top with a generous amount of lemon curd (half at least, if not all!) smoothing it over top, and then garnish with fresh raspberries.
Nutrition
Marlene says
I love the simplicity of this cake -- no complicated fillings or artful swirls of buttercream, just a good honest cake, decadent lemon curd and those berries. Beautiful!
Liliana says
Whenever I make a sponge cake, I always serve it with home-made lemon curd and berries - my family's favourite dessert.
Your cake looks lovely. I would never have thought that mashed potatoes was the secret ingredient. I am looking forward to making it and sieving it to my family. Thanks for sharing.
astrid says
In using the mashed potato, do you let it fully cool down or do you use it fresh and warm? In Irish potato pancakes, it makes a big difference as chilling the potato retrogrades the starch preventing gumminess. Also, you are correct that using different potatoes will give drastically different results due to their very different starches. The use of a waxy potato in potato pancakes make for a horribly dense and gummy outcome. It can be difficult just looking at a picture to know if you used a waxy (I suspect not) a floury (like russet and others) or something in the middle. Can you be more precise in the type of potato you used. Also, what does the sorghum flour do for the recipe? It is not something I usually have on hand. Why did you think baking in the 9" cake pan is easier or better than the 8" springform other than the shorter time?
Janice says
Hi Astrid, here's a link to a post where I describe the steps behind developing this recipe: https://bakeschool.com/developing-a-gluten-free-cake-the-process/
Thanks for your comments. I don't think I was clear enough about how I used the mashed potatoes. I boiled a bunch of peeled potatoes until they were very soft, then I passed them through a ricer to "mash" them. I let the mashed potatoes cool completely (adding no butter, nor any milk), and then when they were cooled, I weighed out what I needed and added it to the cake batter.
The potatoes I used had a yellow flesh and were round. They weren't called Yukon Golds, but I suspect they are a very similar type, which is a less floury, more moist.
I used the sorghum flour to help reduce the amount of moisture in the cake batter. I made several attempts before trying sorghum (which is a good, general gluten-free flour that many gluten-free bakers like to use). I suspect even millet would work (or perhaps even rice flour or potato flour), but the texture and mouthfeel would be different. The sorghum was affordable (especially compared to the xanthan!).
As for the pan size, with this quantity of batter, the springform pan was more than 3/4 full, so it took longer to bake, and I personally find it more difficult to get a fully, well cooked center when the cake pan is so full.
Hope this helps and if you need anything more, let me know!
Curious says
Your recipe sounds very interesting. I often try GF recipes when entertaining a Gluten Intolerant family member and find it stressful not just for the responsibility but also financially, as GF flours and xantham gum are so expensive (especially since you can only buy a package when I might only need a tablespoon, every few months!) I'm curious about the mashed potatoes. Forgive my ignorance, I should probably know the answer anyway, but is it simply potatoes that have been mashed, or "mashed potatoes" (ie: with milk)?
Janice says
Hi! Thanks for stopping by! You are right. As somebody else pointed it out, it wasn't clear what "type" of mashed potatoes I used.
Basically, I boiled the peeled potatoes til they were nice and soft, and then I passed them through a ricer. I let the "mashed" potatoes cool completely before weighing out what I needed and adding them to the cake batter. So, the mashed potatoes were plain: no milk and no butter.
Hope that helps 🙂