A tender buttermilk layer cake gets a spiced rum soak, a rum buttermilk buttercream and a crown of crushed Butterfingers. It’s homey, a little boozy and the best thing that can happen to the mini candy bars in the trick-or-treat bag.

What puts a Butterfinger bar at the top of the Halloween candy list? Maybe it’s the crunchy, flaky center. Maybe it’s the buttery, caramelized, peanut-buttery flavor lurking behind that thin layer of chocolate. Or maybe it’s that many of us don’t permit ourselves the treat of candy except at Halloween. And Valentine’s Day. And Easter. Hmmm. Maybe scratch that thought about discipline and deprivation.

Whatever your stance on candy, this Butterfinger cake transcends any no-sugar aspirations you might be harboring. It starts with two tender buttermilk cake layers, soaks them with spiced rum, then covers them in a rum buttermilk buttercream and a shower of crushed Butterfingers. It’s homey and nostalgic, and it tickles the taste buds in intriguing ways.

About Our Butterfinger Cake

Who knew that buttermilk and spiced rum could combine so delightfully? Buttermilk brings a gentle tang that keeps a very sweet cake from tasting one-note. Spiced rum brings warmth: vanilla, clove and cinnamon notes that make the cake taste like fall. Their happy marriage is something to be celebrated, and there’s no better time to walk these two ingredients down the aisle than autumn, when mini Butterfingers call out to you at the grocery store and from the goody bags your children bring home on Halloween night.

Why Buttermilk Makes a Better Layer Cake

Buttermilk is a baker’s secret weapon. Its natural acidity tenderizes the crumb, so the cake stays soft and moist, and its tang balances the sugar in both the cake and the frosting. A splash of buttermilk in the buttercream does the same job there, loosening it to a smooth, spreadable consistency and cutting the richness of all that butter and powdered sugar.

The Rum Soak

Like a classic rum cake, this Butterfinger cake gets its rum after it comes out of the oven. Once the layers have cooled, pour spiced rum evenly over the tops. The cake drinks it in, adding moisture and a warm, spiced flavor to every bite. For even soaking, poke the tops of the layers all over with a wooden skewer before you pour.

The Ingredients Behind the Flavor

Butter and sugar. Creamed until light and lofty, they trap air that helps the cake rise.

Almond and vanilla extracts. Almond extract adds a warm, bakery-style aroma that plays beautifully with the peanut butter notes of the Butterfingers.

Buttermilk. The source of the cake’s tenderness and tang.

Nutmeg. Just a quarter teaspoon, enough to echo the spices in the rum.

Spiced rum. Used twice: poured over the baked layers and whipped into the frosting.

Mini Butterfingers. Crushed and scattered over the top, they add crunch and that unmistakable flaky, peanut-buttery candy center.

How to Make Rum Buttermilk Butterfinger Cake

Start at room temperature. Take the butter, eggs and buttermilk out of the fridge about an hour ahead. Room-temperature ingredients blend smoothly and give you a fluffier cake and a silkier frosting.

Mix and bake. Cream the butter and sugar, beat in the eggs, extracts and buttermilk, then mix in the dry ingredients just until smooth. Divide between two pans and bake until a skewer comes out clean.

Cool and soak. Let the layers cool completely, then pour the rum evenly over them.

Whip the frosting. Beat the butter and powdered sugar, add the rum and vanilla, then add buttermilk a little at a time until the frosting is smooth and spreadable.

Crumb coat, then frost. Spread a thin layer of frosting over the whole cake and chill it for 15 minutes. This crumb coat locks in loose crumbs, so the final layer of frosting goes on clean. Finish with the rest of the frosting and the crushed Butterfingers.

How to Serve Butterfinger Cake

Serve slices at room temperature, when the buttercream is soft and the cake is at its most tender. Coffee is the natural partner for something this sweet, and for an adults-only cake, make it TABLE’s Spiked Cardamom Coffee. Fresh espresso, vodka, cardamom simple syrup and a splash of cream give it a warm, aromatic spice that echoes the rum and nutmeg in the cake, while the deliciously bitter espresso cuts through all that buttercream. It’s a natural for Halloween parties, fall birthdays or any evening that calls for cake and candy at the same time.

Make-Ahead and Storage Tips

• Make the frosting up to three days ahead and refrigerate it. Allow an hour or two for it to come back to room temperature, then rewhip before using.
• Bake the layers a day ahead, wrap them tightly once cool and store at room temperature. Soak with rum before assembling.
• Store the finished cake covered in the refrigerator for up to three days. Let slices sit out for about 30 minutes before serving.
• Add the crushed Butterfingers shortly before serving; they soften as they absorb moisture from the frosting.

Butterfinger Cake FAQs

Does the rum cook off?

No. The rum is poured over the cake after baking and whipped into the frosting uncooked, so the alcohol stays in. This is an adults-only cake.

What size cake pans should I use?

Two 9-inch round cake pans. Grease and flour them and line the bottoms with parchment for the easiest release.

Can I use a different candy bar?

Yes. Any crunchy candy bar from the Halloween bag works as a topping. Butterfingers are our favorite because their peanut-buttery crunch pairs so well with the rum.

What if I don’t have buttermilk?

Stir 1 tablespoon of lemon juice or white vinegar into 1 cup of milk and let it stand for 5 to 10 minutes until slightly thickened.

Why do the ingredients need to be at room temperature?

Cold butter won’t cream properly, and cold eggs or buttermilk can make the batter look curdled. Room-temperature ingredients blend smoothly, which means a lighter cake and a silky buttercream.

More Halloween candy desserts from TABLE: 

Try out our other Halloween candy desserts like Rum Pecan Candy Corn Blondies, Halloween Espresso Brownies, and Halloween Coffee Cake.

Rum Buttermilk Butterfinger Cake

---

• Author: Keith Recker
• Total Time: 3 hr 45 min
• Yield: 16 slices 1x

Print Recipe

Description

A tender two-layer buttermilk cake soaked with spiced rum, frosted with rum buttermilk buttercream and topped with crushed Butterfingers. A grown-up home for Halloween candy.

---

Ingredients

Scale 1x2x3x

For the cake:

• 3/4 cup (1 1/2 sticks) unsalted butter, at room temperature
• 1 1/2 cups granulated sugar
• 3 large eggs, at room temperature
• 1 1/2 tsp almond extract
• 1/2 tsp vanilla extract
• 1 cup buttermilk, at room temperature
• 2 1/2 cups King Arthur unbleached all-purpose flour
• 2 1/2 tsp baking powder
• 1/2 tsp salt
• 1/4 tsp ground nutmeg
• 1/3 cup spiced rum, for soaking after baking
• 6 mini Butterfinger bars, crushed, for garnish

For the frosting:

• 2 cups (4 sticks) unsalted butter, at room temperature
• 8 cups powdered sugar
• 2 tsp vanilla extract
• 1/4 cup spiced rum
• Up to 4 tbsp buttermilk, at room temperature

Cook Mode Prevent your screen from going dark

---

Instructions

For the cake:

1. Bring to room temperature. Let the butter, eggs and buttermilk come to room temperature, about 1 hour.
2. Prep the pans. Preheat the oven to 350°F. Grease and flour two 9-inch round cake pans and, if you like, line the bottoms with parchment paper.
3. Cream the butter and sugar. In a stand mixer fitted with the paddle attachment, cream the butter and sugar until light and lofty, 3 to 4 minutes.
4. Add the eggs. With the mixer running, add the eggs one at a time, beating well after each.
5. Add the wet ingredients. Add the almond extract, vanilla extract and buttermilk and beat until smooth.
6. Add the dry ingredients. Add the flour, baking powder, salt and nutmeg and mix until just smooth, scraping down the sides of the bowl so everything is combined.
7. Bake. Divide the batter evenly between the pans. Bake for about 30 minutes, until a wooden skewer inserted in the center comes out clean.
8. Cool. Let the layers cool completely before removing them from the pans.
9. Soak with rum. Pour the 1/3 cup rum evenly over the tops of the two layers.

For the frosting:

1. Whip the butter and sugar. Using the whisk attachment, whip the butter and powdered sugar until completely combined.
2. Add the rum and vanilla. Add the rum and vanilla extract and mix well.
3. Adjust with buttermilk. Add the buttermilk gradually, just until the frosting is smooth and spreadable. You may not need all 4 tablespoons.
4. Make ahead if you like. The frosting can be refrigerated for up to 3 days. Allow an hour or two for it to return to room temperature before using.

To assemble:

1. Anchor the first layer. Place a small dab of frosting on a cake plate and set the first layer on top.
2. Fill. Spread a layer of frosting over the top, then set the second layer on top.
3. Crumb coat. Frost the entire cake with a thin layer of frosting and refrigerate, uncovered, for 15 minutes.
4. Finish. Spread on the remaining frosting and sprinkle the crushed Butterfingers over the top.
5. Serve. If the cake has been refrigerated, let it come close to room temperature before serving.

• Prep Time: 45 min
• Additional Time: 2 hr 30 min
• Cook Time: 30 min
• Category: Dessert
• Method: Baking
• Cuisine: American

Nutrition

• Serving Size: 1 slice
• Calories: About 720

About the Recipe Author and Photographer

Keith Recker is Editor in Chief and Co-Owner of TABLE Magazine. A color and trend forecaster for nearly 20 years, his clients have included Pantone, WGSN, Stylus, and the Color Association of the United States. He is the author of three books on color, including Deep Color: The Shades That Shape Our Souls and True Colors: World Masters of Natural Dyes and Pigments, and co-founder of the Open Source Colour Association. Read more of his work here or contact him at keith@tablemagazine.com to discuss his sweet tooth.

Subscribe to TABLE Magazine‘s print edition.