This cake is fall in a nutshell. A large nutshell because this is a get together sort of cake, made for the weekend and a nice groups of friends. It is a feast for the eyes and nourishing to the palate.
It combines the end of summer blackberries with the autumnal signals of apples and squash. It is a transition cake. The humble squash, rather than the flashy pumpkin is used as the base note flavour in this recipe. The pumpkin spiced latte has generated an obsession with all things pumpkin this time of year which leads to overlooking other wonderful produce that are equally great in baking. I get it though, there likely isn’t a huge market for the squash spiced latte. What do you think?
In a taste test between the two, I find butternut squash to be a bit sweeter. I enjoy seasonal butternut squash plain, without any seasoning. Admittedly, this taste preference was probably developed from preparing and taste-testing homemade baby food but that is another story.
Whipped mascarpone frosting is a lighter alternative to buttercream or cream cheese frosting. Comparatively, the cake does not feel heavy in the way that a carrot cake often does. So go on, have a large slice!
This recipe was inspired by a charming post by Aimee Twigger at Twiggstudios in England. I have admired her work for a long time. Thank you.
Blackberry, Apple and Butternut Squash Cake with Whipped Mascarpone Frosting
Makes a 4-layer 20cm cake
Time: Prepping squash (1 hour), Cake 25 minutes plus baking time (46 minutes), Frosting (15 minutes)
Ingredients
Cake
228g (1 cup) unsalted butter, room temperature
180g (1 cup) spooned and levelled brown sugar*
200g (1 cup) granulated sugar
3 large eggs, room temperature
420g (1 ¾ cups) pureed butternut squash
130g (1 cup) peeled and grated soft apple (I used McIntosh)
420g (3 cups) all-purpose flour
10g (2 tsp) baking powder
5g (1 tsp) baking soda
3g (1/2 tsp) fine sea salt
6g (2 tsp) cinnamon
76mL (1/3 cup) whole milk
135g (1 cup or 1 small clam shell container) fresh blackberries, cut in half (save 5-7 whole berries for decoration)
Frosting
475g (2 ¼ cups or 1 large container- I used TreStelle) mascarpone
58g (1/4 cup) unsalted butter, room temperature
250g (2 cups) icing sugar
5mL (1 tsp) vanilla extract
473mL (2 cups) whipping cream
Directions
Cake
1. Prepare the butternut squash. Preheat oven to 375°F (190°C). Thinly cut the bottom and top off. Cut in half lengthwise, brush with oil and place open-side down on a rimmed baking sheet with a bit of water. Bake for 45 minutes or until soft. Cool slightly then remove seeds. Scoop out the flesh and puree in a food processor or blender until smooth.
2. Measure all of the ingredients and allow eggs and butter to come to room temperature.
3. Prepare 2 -20cm (8 inch) springform pans or cake tins by brushing them with melted butter and lining them with parchment paper.
4. Preheat oven to 350°F (175°C).
5. Cream the butter and sugars in a large bowl using a stand or hand mixer until pale and fluffy.
6. Beat the eggs in one at a time until fully incorporated.
7. Mix in the butternut squash and grated apple.
8. Whisk together the flour, baking powder, baking soda, salt and cinnamon in a separate bowl.
9. Fold in half of the flour mixture followed by half of the milk. Repeat.
10. Fold in the blackberries.
11. Pour into prepared pans and back for 40-46 minutes, until a skewer inserted into the middle of the cake comes out clean.
12. Set on wire rack to cool and remove sides once cooled.
Frosting
1. Whisk the mascarpone, butter, and icing sugar in a stand mixer with whisk attachment or using a hand mixer.
2. Scrape the sides and bottle of the bowl. Add the vanilla.
3. While the mixer is on, slowly add the whipping cream. Once incorporated, turn the mixer to high speed and mix until soft peaks form. Depending on the temperature of the ingredients, this may happen quickly. If over-mixed, the frosting will curdle or separate.
4. Transfer into a piping bag.
Cake Assembly
1. Trim the tops of the cakes using a sharp, serrated knife and gently seesawing it back and forth.
2. Cut each cake horizontally in half making sure each piece is even (this takes practice).
3. Place one of the bottom layers, cut side up, on a cake plate. Pipe a boarder of frosting around the outside and then fill in the middle. Add the next layer on top. Repeat and refrigerate the cake to firm up the frosting (about 15 minutes).
4. Mask the sides and top of the cake with the remaining frosting. You will likely have some leftover. Refrigerate again.
5. Decorate with remaining blackberries, flowers, etc.
Notes
* Typically, brown sugar is firmly packed but in this recipe, I have suggested to spoon the brown sugar into your measuring cup and then level it off.
