Butterscotch Crunch Cake

image of a slice of butterscotch toffee cake on a plate that's been cut into to show it's delicious filling

5 from 3 ratings

Butterscotch Crunch Cake

This butterscotch crunch cake is made with tender brown sugar cake layers, crunchy brown sugar toffee bits and candied pecans, fluffy butterscotch Swiss meringue frosting, and generous butterscotch drizzles.

Prep Time1

Cook Time34

Additional Time1

Total Time2 34

Course: Cakes

Cuisine: American

Servings: 24

Calories: 672kcal

Author: Chelsey White

Ingredients

Brown Sugar Cake Layers

3 cups all-purpose flour 390g
1 1/2 cups granulated sugar 300g
1 1/2 cups packed light brown sugar 300g
2 1/2 tsp baking powder 10g
1 tsp fine salt 6g
1/2 cup (1 stick) unsalted butter, room temperature 113g
4 large eggs, room temperature 224g
1 cup full-fat sour cream, room temperature 240g
1/2 cup buttermilk, room temperature 120g
1/2 cup vegetable or canola oil 110g
1 tsp vanilla extract or vanilla bean paste 4g

Butterscotch Sauce

1/2 cup unsalted butter 113g
1 cup packed dark brown sugar 200g
1 cup heavy whipping cream, room temperature 240g
1 tsp fine salt 6g
1 tsp vanilla extract or vanilla bean paste 5g

Butterscotch Toffee Crunch

1/2 cup (1 stick) unsalted butter, room temperature 113g
1 cup packed light brown sugar 200g
1 tsp fine salt 6g

Butterscotch Frosting

8 large egg whites, room temperature 240g
2 1/2 cups granulated sugar 500g
2 cups unsalted butter, room temperature 452g; 1 lb. box
1/2 cup butterscotch sauce - recipe above 140g
2 tsp vanilla extract or vanilla bean paste 8g
1/2 tsp fine salt 3g

Optional Filling

1 cup toasted pecans, finely chopped 120g

Instructions

Brown Sugar Layers

Start by preheating the oven to 350°F / 175°C and lining three 8" pans with parchment rounds and grease with non-stick baking spray. Set aside.
Whisk 3 cups flour, 1 1/2 cups packed light brown sugar, 1 1/2 cups granulated sugar, 2 1/2 tsp baking powder, and 1 tsp salt in a large bowl or the bowl of a stand mixer.
Mix 1/2 cup of unsalted butter slowly into the dry ingredients on a low speed. Continue to mix until no large chunks of butter remain.
In a separate bowl, whisk together 4 large eggs, 1 cup sour cream, 1/2 cup buttermilk, 1/2 cup vegetable oil, and 1 tsp of vanilla extract.
Slowly pour the wet ingredients into the dry ingredients and mix on a low speed until incorporated.
Scrape down the sides of the bowl with a rubber spatula, then beat on a medium speed for 30 more seconds to make sure everything is properly mixed together.
Divide the batter evenly between the prepared pans (600g per pan if you're making 3 layers). Bake for 32-35 minutes or until a toothpick comes out with a few moist crumbs. Let the pans cool for 10 minutes, then run a small offset spatula around the perimeter of the pan to separate the cake from the pan.
Then flip the cake layers onto a wire rack to finish cooling. Use a serrated knife to level the tops of the layers once they're fully cooled.
If you make these cake layers in advance and freeze them, let them thaw for about 20 minutes before making your cake. The cake layers should still be slightly cold to the touch, which will make it easier to assemble your cake.

Butterscotch Sauce

Next, make the butterscotch sauce. Turn the stove to medium heat, and place a pot over the element.
Melt 1/2 cup of butter in a medium-sized, heavy-bottomed saucepan over medium heat. Note: Do NOT use a non-stick pan for this recipe!
Add 1 cup packed dark brown sugar, 1 cup of heavy cream, and 1 tsp salt. Stir the mixture with a rubber spatula until it's fully combined. Let the mixture come to a boil, scraping down the sides and bottom of the bowl occasionally with a rubber spatula. Let the mixture boil for 4 to 5 minutes.
Then remove it from heat and stir in 1 tsp vanilla extract. The butterscotch will be thin at this point, but it will thicken as it cools. Pour into a separate container, then set it in the fridge to cool until it reaches room temperature. You should end up with about 1 1/2 cups of butterscotch sauce.

Butterscotch Toffee Crunch

While the butterscotch sauce cools, make the brown sugar toffee bits. Line a small rimmed baking sheet with parchment paper or a silicone baking mat and set aside.
Melt 1/2 cup of unsalted butter in a heavy-bottomed, small saucepan over medium heat. Add 1 cup of packed light brown sugar and 1 tsp fine salt, and whisk vigorously until combined. Continue to stir the mixture constantly as it cooks. If the mixture separates while it's cooking, remove it from the stovetop and whisk vigorously until it comes back together. Then return it to heat and continue cooking it.
Cook the mixture for about 7 minutes, until it reaches 295°F or 146°C.
Pour the mixture onto the prepared baking pan as soon as it reaches the right temperature. It should spread out into an even layer. Set aside to cool for about 20 minutes.
At this point, the toffee should be hard to the touch. Place the toffee in a Ziplock bag and use a rolling pin or heavy object to break it into small pieces. I recommend placing a towel underneath the toffee to protect your counters. If you make this in advance, store it in an airtight container/bag for up to 1 week.

Butterscotch Frosting

Once the butterscotch sauce is at room temperature, make the butterscotch frosting. In a medium-sized pot, add about 1 inch of water and bring to a simmer. Add 8 egg whites and 2 1/2 cups of granulated sugar into a large metal bowl.
Place the bowl on top of the pot filled with simmering water. The bowl should create a seal over the pot. Make sure the water isn’t touching the bottom of the bowl, or it can cook the egg whites.
Whisk the mixture constantly for about 3 minutes, until it reaches 160°F / 71°C. You can test the mixture to see if it’s ready by rubbing a tiny bit between your fingertips. The sugar should be fully dissolved, and it should feel super smooth and hot to the touch.
Once it reaches this stage, lift the bowl away from the pot and dry the bottom with a towel. Pour the mixture into the bowl of a stand mixer and beat on a medium-high speed with a whisk attachment. Mix for about 10 minutes, or until you have stiff, glossy peaks that stick straight up. While the meringue whips, I like to add something cold around the base of my bowl. I find the meringue stays quite warm while it whips up and placing a bag of frozen veggies around the base of the bowl helps cool it back to room temperature. This can prevent your buttercream from becoming soupy in the next step.
Mix in 2 cups of unsalted butter at a medium speed, one stick at a time. Scrape the sides and bottom of the bowl with a rubber spatula as needed. The frosting should have a thick, whipped consistency once all the butter is mixed in. If it looks lumpy or broken, keep mixing until it looks fluffy and thick. If it doesn't seem to come together after an additional 10 minutes of mixing, check out the troubleshooting section in this post.
Once the consistency is right, swap out the whisk attachment for a paddle attachment and add 1/2 cup of room temperature butterscotch sauce, 2 tsp vanilla extract, and 1/2 tsp fine salt. Continue mixing on a low speed for a couple of minutes to make the frosting extra smooth.

Assembling this Butterscotch Crunch Cake

Then it's finally time to assemble the cake! Stack and frost the brown sugar cake layers on a greaseproof cake board or flat plate using a dab of frosting to help stick the first cake layer to the board.
Spread an even layer of butterscotch frosting on top of the first cake layer. Drizzle about 1/2 cup of the butterscotch sauce on top of the frosting, then sprinkle on a few spoonfuls of the toffee bits and toasted pecans. Repeat this process with the remaining cake layers.
Chill the cake in the freezer for 10 minutes once the cake layers are stacked to help lock the filling in place and make it easier to frost the cake.
Then spread a thick coat of butterscotch frosting around the cake using a large offset spatula to give it a beautiful textured finish. Sprinkle some of the toffee bits and pecans in a ring around the top of the cake, then enjoy!

Video

Notes

Note: This recipe can be made with a stand mixer or hand mixer. I like to use the paddle attachment when making the batter, but you can also use a whisk attachment or a large bowl and hand mixer.

How Many People Does This Cake Feed?

If you make this cake with 3, 8-inch cake layers or 4, 7-inch cake layers, it will feed about 24 people. For more information on cake sizes and servings, check out my cake portion guide.

Recipe Variations - Making This Cake in Different Sizes

One batch of this recipe makes about 10 cups of batter or about 1800 grams. If you plan to use three circular cake pans, add 600 grams of batter into each pan.

If you want to make a tiered cake or different-sized cake with this recipe, check out my cake batter calculator to see how many batches of batter you'll need.

This recipe can also be used to make a sheet cake! One batch will make a 1, 9 x13-inch cake layer that's about 1.5 inches tall once leveled.

Bake for 45-55 mins at 350 F / 175 C, or until a toothpick inserted in the center comes out with a few moist crumbs. Bake time can vary a lot based on the type of pan you use, if you use heating cores, and your oven. I recommend using heating cores if you have them, they help sheet cake layers bake more evenly and quickly.

For more details on how to convert this cake recipe and others into sheet cakes, check out my sheet cake guide.

Last but not least, you can also make cupcakes using this recipe. Fill the liners 3/4 full and bake them at 350 F / 175 C for 19-21 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs.

Tips for Making the Best Butterscotch Crunch Cake

Be sure to properly measure the flour (spoon into the cup measure, then level) or use a kitchen scale.
Make sure the ingredients are at room temperature to help them mix together better.
If possible, use a candy thermometer to make the butterscotch crunch. You need the sugar to reach the right temperature.
Don't level and torte the cake layers until they are completely cooled.
If your cake layers turn out less than perfect, read my cake troubleshooting guide to see where things might've gone awry.

Making This Cake in Advance and Storage Tips

I highly recommend making the cake layers in advance and freezing them. It breaks the process up and makes it more approachable.

You can also make the frosting ahead of time or save any leftover frosting! It can be stored in an airtight container in the fridge for up to a month, or in the freezer for up to 3 months. Be sure to give it a good stir once it thaws to get the consistency nice and smooth again.

The butterscotch toffee can be stored in an airtight container or ziplock bag at room temperature for up to a week. If any of the bits stick together, they can be broken up with a fork.

The butterscotch sauce can be made up to 2 weeks in advance and stored in an airtight container in the fridge.

A frosted cake can last in the fridge for up to a week, or in the freezer for up to a month. The buttercream locks in all the moisture, keeping the cake fresh and delicious!

If you cut into the cake and have leftovers, use any remaining frosting to cover the cut section to keep it moist and store it in the fridge for up to a week.

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