Looking for a gloriously BIG, LIGHT, FLUFFY, EASY, NO FUSS cake to feed a crowd at your next celebration? This is the recipe you need. There is no packaged fondant, fancy layering or intricate piping involved. This gluten free slab cake (also known as ‘sheet cake’) is so quick and easy to whip up and delivers what most kids and adults love best – a simple light and fluffy sponge smothered in a smooth buttercream frosting. My Strawberry Swirl Gluten Free Slab Cake feeds up to 30 guests and features a luscious REAL strawberry frosting. No fake stuff here.
A few essential tips before you get started –
- Line your rectangular baking tray with baking paper to make the cake easier to flip out. The cake is large so you don’t want to risk it getting stuck.
- To create a marbled swirl dollop the pink and white cake batter side by side in the baking tray. Run a butter knife through the batter but do not over swirl the batter or the colours will start to combine.
- Ensure your strawberry puree is completely cool before adding it to your buttercream otherwise it will melt your frosting. You can even prepare the puree the day prior and pop it in the fridge, just bring it to room temperature prior to mixing. Don’t over mix the strawberry puree at the final stage or your buttercream may curdle.
- I use a good quality plain gluten free flour to ensure a light and fluffy sponge. My preferred brand is Bob’s Red Mill 1 to 1 plain baking flour. You can swap gluten free flour for plain flour if you just want a regular cake.
- For a light and fluffy buttercream frosting beat your butter first with a whisk attachment for 5 minutes before adding the icing sugar. This technique incorporates more air into the buttercream making the frosting fluffier. If your frosting is too runny add more icing and if it is too thick add more puree.
That’s as hard as it gets. Enjoy!
Gluten Free Strawberry Swirl Slab Cake Recipe
Cook time:
Total time:
Serves: 30 slices
Ingredients
- Cake
- 450g or 1¾ cups unsalted butter, softened
- 450g or 2 cups caster sugar
- 1 tbs vanilla extract
- 6 eggs
- 450g or 3½ cups plain gluten free flour*
- 1½ tbs baking powder
- Pink colouring
- Strawberry Buttercream Icing
- 300g icing sugar mixture, sifted
- 280g unsalted butter, softened
- 2 - 3 tbs cooled strawberry puree (150g fresh strawberries + 1 tbs caster sugar)
- * I use Bob's Red Mill 1 to 1 plain gluten free baking flour
Instructions
Conventional Method
- Preheat oven to 180c and line a greased 25 x 30 cm rectangular baking tin with baking paper.
- Make strawberry puree by combining strawberries and sugar in a saucepan and simmering over low heat for 10 minutes. Set aside to cool and then blitz to a puree.
- Beat butter, sugar and vanilla until pale and creamy in a mixer. Add eggs one at a time with mixer running.
- Add flour and baking powder and mix until just combined. Split the mixture between two bowls to create a white batter and pink batter. Add pink colouring into one bowl for a pink batter.
- Using a large spoon place a large dollop of each batter in the tin and create a swirl pattern by gently running a butter knife through the batter in a twirly pattern.
- Bake cake in the oven for 40 - 45 min or until skewer comes out clean. Cool completely.
- To make the buttercream beat butter with whisk attachment for 5 min until fluffy. Slowly add in the icing sugar until fully incorporated. Add strawberry puree at room temperature and beat for a few seconds until just combined (don’t beat puree too long or it may curdle). Spread icing over cooled cake.
Thermomix Method
- Preheat oven to 180c and line a greased 25 x 30 cm rectangular baking tin with baking paper.
- Make strawberry puree by combining strawberries and sugar in Thermomix bowl and cooking 5 min/100C/speed1. Blitz for 3 sec/speed 5 to form a puree. Set aside to cool.
- Beat butter, sugar and vanilla until pale and creamy in clean Thermomix bowl for 1 min/speed 4. Add eggs one at a time with mixer running on speed 4.
- Add flour and baking powder and mix 30 sec/speed 5 scraping down bowl halfway through mixing. Split the mixture between two bowls to create a white batter and pink batter. Add pink colouring into one bowl for a pink batter.
- Using a large spoon place a large dollop of each batter in the tin and create a swirl pattern by gently running a butter knife through the batter in a twirly pattern.
- Bake cake in the oven for 40 - 45 min or until skewer comes out clean. Cool completely.
- To make buttercream beat butter with whisk attachment 1 min/speed 5 until fluffy. Slowly add in the icing sugar until fully incorporated on speed 4. Add strawberry puree at room temperature and mix 5 sec/speed 3 (don’t beat puree too long or it may curdle). Spread icing over cooled cake.
Hi,
This cake looks great. My daughter is allergic to egg. Have you tried this without egg using an egg substitute? Just wondering what you would recommend or would it not work? My daughter is coeliac and I’m finding most GF recipes have egg in them. Thanks
Hi Alice
Thanks for getting in touch. I have never tried an egg substitute with this recipe. For baked cakes I suggest trying 1/4 unsweetened apple puree for every egg in the recipe. Try this and see how you go. Enjoy!!
I’ve used apple purée in biscuits and works beautifully so should do the trick here I think
Your cake looks pretty amazing! This is my kind of cake, I love it!
Thank you Pat, enjoy my gluten free recipe.
Hi,
Would it be ok to reduce the sugar amount or use a refined sugar alternative?
Hi Tammie
If you are looking for a refined sugar substitute you could make the cake with coconut sugar or something like Natvia. Alternatively, just slightly reduce the sugar quantity. Cheers, Helen.
This recipe looks absolutely delicious! I am wanting to make it as a double layer round birthday cake for my little girl. Would this batter quantity work for 2 x 8 or 10 inch pans and what would the cooking time be? Thank you so much 🙂
Hi Sophie,
Yes it will work in two pans. I would check it at 30 min to see if the cakes are cooked by inserting a skewer and see if it comes out dry.
If you use the smaller pans line them with baking paper above the sides so the cake has room to rise. Enjoy!
This looks delicious, what size pan do you recommend?
25 x 30cm