This raspberry sheet cake is equal parts delicious and easy to make. With a rich, melt-in-your-mouth sponge dotted with raspberries and a pretty raspberry swirled mascarpone frosting, it’s a joy to make and eat.
Sometimes, you just need a no-fuss recipe, you know? The kind of recipe that takes minutes and minimal effort to throw together, with results that comfort and delight.
This is one such recipe. A sweet, just-buttery-enough, lemon zest scented sponge that melts in your mouth, dotted with raspberries that provide a burst of colour and tangy flavour. A mascarpone frosting swirled through with a raspberry reduction, for a finishing touch that’s both rustic and eye-catching.
Don’t let the simplicity of this raspberry sheet cake fool you. As far as desserts go, it’s a memorable one.
Before we get to the bits and bobs of making this wonderful cake – if you like what you’re seeing, subscribe to my newsletter to keep up to date on the latest recipes and tips!
What is a sheet cake?
A sheet cake is a single layer cake baked in a large rectangular baking pan (also called a sheet pan). Sheet cakes are usually served frosted, with frostings such as different flavours of buttercream, chocolate ganache, or whipped cream.
You can, of course, decorate them further with everything from fresh fruit to sprinkles. For extra flavour and texture, you can also mix add-ins into the sponges themselves – think chopped nuts, fruit, sprinkles, or chocolate chips.
How do you make raspberry sheet cake?
This is the perfect recipe to make when that sneaky craving for something sweet and indulgent strikes, but you really can’t be bothered with anything fancy or complicated.
The ingredients for this raspberry sheet cake are the usual suspects, and you probably have most (if not all) of them in your pantry already. (For the full recipe, including the ingredient quantities, scroll down to the bottom of the page.)
- gluten free flour blend
- almond flour
- xanthan gum
- baking powder
- a pinch of salt
- softened unsalted butter
- lemon juice
- lemon zest
- fresh or frozen raspberries
To make the raspberry sheet cake:
- Sift together all the dry ingredients.
- Add the softened unsalted butter and mix it into the dry ingredients until you get a texture resembling coarse sand.
- Add the wet ingredients, and mix until you get a smooth batter.
- Transfer the batter into a lined sheet pan – I like to transfer it in several layers, sprinkling each layer with raspberries to get an even distribution of fruit in each slice.
Seriously, how easy is that?!
Now, you’ll notice that the method is slightly unusual in that the butter isn’t creamed with sugar, but rather added to the dry ingredients. This is the so-called “reverse creaming method”, which I use all the time for my cakes. It gives a very delicate, melt-in-your-mouth crumb with an even aeration.
Basically what that means, is that the air holes/bubbles in the sponge are smaller and even in size – and the sponge is slightly denser compared to one prepared by the “standard creaming method” (where you cream together butter and sugar, then add eggs, etc.). Therefore, the reverse creaming method works wonderfully for buttery, rich cakes such as this one.
How long do you bake a sheet cake?
The exact baking time for a sheet cake will depend on the size of the sheet pan you use. The recipe below is perfect for a 9 x 13 inch (23 x 33 cm) sheet pan, and requires baking at 355 ºF (180 ºC) for about 38 to 40 minutes.
If you scale the recipe up or down, or use a different size of the baking pan, you will need to adjust the baking time accordingly (keeping the oven temperature the same). To check when the cake is done, insert a toothpick or skewer into the middle of the cake. When it comes out clean or with a few stray crumbs attached, the cake is perfectly baked.
How do you make mascarpone frosting?
To make the mascarpone frosting, you only need four ingredients:
- heavy/double cream
- powdered/icing sugar
- mascarpone cheese
- raspberry reduction (see recipe below for more details)
And all you need to do, is whip up the heavy cream with the powdered sugar, fold in the mascarpone cheese, spread the frosting on top of the (cooled) raspberry sheet cake, and swirl through the raspberry reduction for an extra tangy kick (plus, it’s pretty).
And that’s all there is to it. No fuss, no funny ingredients, no complicated method to follow. Just a simple raspberry sheet cake, that’ll have you craving seconds… and thirds.
I hope you’ll love it as much as I do.
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Raspberry Sheet Cake (Gluten Free)
For raspberry sheet cake:
- 2 1/2 cups (300 g) plain gluten free flour blend (I've used Doves Farm Freee plain gluten free flour, which doesn't contain xanthan gum)
- 1 cup (96 g) almond flour
- 3/4 tsp xanthan gum (omit if your gluten free blend already contains xanthan gum)
- 4 tsp baking powder
- 1 1/2 cups (300 g) caster/superfine sugar
- 1/2 tsp salt
- zest of 2 lemons
- 3 sticks (339 g) unsalted butter, softened
- 6 medium eggs, room temperature
- 3/4 cup + 1/2 tbsp (190 mL) milk, room temperature
- 1 tsp vanilla paste (or 2 tsp vanilla extract)
- 1 tbsp lemon juice
- 1 1/2 - 2 cups (330 - 450 g) frozen raspberries
For mascarpone frosting:
- 1 cup (225 g) frozen raspberries
- 1 1/4 cup (300 mL) double/heavy cream
- 3/4 cup (90 g) powdered/icing sugar
- 1 cup (225 g) mascarpone cheese
- 1 tsp vanilla paste (or 2 tsp vanilla extract, optional)
For raspberry sheet cake:
- Pre-heat the oven to 355 ºF (180 ºC) and line a 9 x 13 inch (23 x 33 cm) rectangular sheet pan with baking/greaseproof paper.
- In a large bowl, sift together the gluten free flour blend, almond flour, xanthan gum and baking powder. Add the sugar and salt, and mix until combined.
- Add the softened butter and, using either a stand mixer with the paddle attachment or a hand mixer with the double beater attachments, work the butter into the dry ingredients until you get a texture resembling coarse sand.
- Add the lemon zest. In a separate bowl, mix together the eggs, milk, vanilla and lemon juice. Add the wet ingredients to the dry+butter mixture, and whisk/mix well until you get a smooth batter with no flour clumps.
- Transfer the cake batter into the prepared sheet pan. I recommend doing this in several layers, sprinkling each layer with the frozen raspberries to get an even distribution of fruit in each slice.Smooth out the top, sprinkle with any remaining frozen raspberries, and bake in the pre-heated oven at 355 ºF (180 ºC) for about 38 - 40 minutes or until risen, golden brown on top and an inserted toothpick comes out clean.If the cake starts browning too quickly or too much, cover it with aluminium foil and continue baking until done.
- Allow to cool in the sheet pan for about 10 minutes, then remove from the pan, and allow to cool completely on a cooling rack. (Alternatively, you can leave it in the sheet pan to cool completely – this will depend on how you want to serve the sheet cake.)
For mascarpone frosting
- First, make the raspberry reduction:In a saucepan, cook the raspberries on medium-high heat until they have released their juice and part of the liquid has evaporated.Pass the raspberry mixture through a sieve to remove the seeds and skin.Return the raspberry juice to the saucepan and cook further until it has decreased in volume to about 1/4 - 1/3 cup.Allow to cool.
- In a big bowl, whip together heavy/double cream and powdered sugar until soft peaks form. You can use a stand or hand mixer – or even do it by hand.
- Once at the soft peak stage, fold in the mascarpone cheese. You will get a smooth frosting that spreads easily but will also hold its shape. Add in the vanilla paste (optional) and mix until it's evenly distributed.
- Spread the frosting on top of the cooled raspberry sheet cake, and swirl through the cooled raspberry reduction.
- The raspberry sheet cake keeps well covered in cling film (or in a closed container) in a cool dry place for 3 - 4 days.