If you hate walnuts, now might be a good time to move on. If you’re ambivalent about walnuts, though, and just waiting to be convinced…
Walnut cake made an appearance on the Great British Bakeoff this year, and I was intrigued but just couldn’t quite bring myself to pair it with the traditional boiled icing (“white tar icing,” as my friend and fellow GBBO fanatic Mary calls it). The caramelised walnuts used as a garnish got me thinking about alternative icings, and this British-American fusion cake came into being. A classic walnut cake, which is a staunchly British institution, paired with a salted caramel buttercream icing– a trademark American flavour. Perfection. I’ve made it a few times now, and it is quickly earning itself a place in the regular rotation.
I used one of Sally’s layer cakes (Sally’s Baking Addiction is one of my go-to blogs!) as a base recipe, switching out her stir-ins of raspberries and chocolate chips and opting instead for finely chopped walnuts. For the icing, I adapted this recipe from BBC Good Food, but can I be honest? Follow my instructions, not theirs. I threw out a few botched batches of caramel before piecing together some information (10 minutes! Don’t stir!) that would have been helpful.
The cake itself was fairly straightforward, and you’ll find the recipe below. Once it is in the oven, you can get started on your caramel. If you’ve never made caramel before, don’t panic! It can be a touchy process, but if you avoid a few common mistakes you’ll be fine. Nothing compares to homemade caramel.
Whisk the sugar and water together in a saucepan over medium-low heat until the sugar has dissolved completely. THEN PUT THE WHISK DOWN AND DON’T PICK IT UP AGAIN. (Mistake #1: whisking while caramelizing will cause your caramel to seize and turn into white, snowy-looking cement.)
Increase the heat to medium-high, bring the mixture to a gentle boil, and just let it simmer… (Mistake #2: impatience will kill you here. Don’t hover, but don’t walk away. Just check on the colour every few minutes.)
Watch the bubbles grow stickier…
And eventually turn a gorgeous golden-brown! Remove from the heat while it’s still on the golden side of golden brown. (Mistake #3: overcooking your caramel will leave a bitter, burnt taste in your final product.)
At this point, smoothly and carefully pour your cream into your caramelized sugar while whisking to combine. Whisk vigorously until it all comes together. It’s going to splatter and fuss for a minute, but carry on whisking until the magic happens and it all turns a beautiful, creamy caramel colour.
Whisk in the salt and vanilla, and set the mixture aside to cool completely.To make your icing, cream the butter and icing sugar together until light and fluffy…Add your caramel…
And mix until combined.
You can give it one last minute on a high speed at the end to fluff it up.
Assemble, ice, devour!
Salted Caramel Walnut Cake
Makes 3 8-inch or 2 10-inch layers
For the cake layers:
3 1/4 cups (405g) plain flour
1 tsp baking powder
1/2 tsp baking soda
3/4 tsp salt
1 cup (230g) unsalted butter, melted
1 3/4 cup (350g) caster or granulated sugar
2 eggs, room temperature
2 cups (480ml) buttermilk
2 tsp vanilla extract
2 1/2 cups (400g) walnut pieces, finely chopped
For the icing:
1 1/8 cup (250g) caster or granulated sugar
2/3 cup (160ml) double or heavy cream
1 tsp salt
2 tsp vanilla extract
1 1/3 cup (300g) salted butter, softened
3 cups (375g) icing sugar
- Make the cake layers: Preheat oven to 175°C (350°F). Grease and flour your cake tins. Line bottom with a parchment circle for easier removal.
- Whisk dry ingredients (flour, baking powder and soda, salt) together in a large bowl and set aside. In a medium bowl, vigorously whisk melted butter together with sugar until mostly dissolved. Add eggs, buttermilk, and vanilla, and whisk thoroughly to combine. Add the wet ingredients to the dry and mix gently until just combined (using a whisk will help you to avoid overmixing). Fold in walnuts until evenly incorporated.
- Divide batter evenly among prepared cake tins and bake until set (a toothpick inserted in the center should come out with just a few moist crumbs) and lightly browned. This should take between 18-24 minutes, but the exact time will vary depending on the size of your cake tins. Allow cakes to cool in pans.
- Make the caramel: Whisk sugar and water together in a saucepan over medium-low heat until sugar has dissolved completely. Increase heat to medium-high and allow to simmer untouched (do not stir!) until mixture thickens and turns golden-brown. This will take between 10-20 minutes, depending on your pan and stovetop. Remove pan from heat and pour in cream (mixture will bubble and spit– watch your hands!), whisking as you pour. Add salt and vanilla, adjusting to taste, and set mixture aside to cool completely.
- Make the icing: Cream butter and icing sugar together until smooth and fluffy (4-5 minutes). Add cooled caramel and mix on low until combined, then on high for 1 more minute.
- Decorate and serve!