Biscoff Cake with Cookie Butter Frosting That Stays Moist for Days (The Only Layer Cake Recipe You Need)
This spiced brown sugar layer cake is brushed with a warm cookie butter soak, then frosted with an impossibly creamy cookie butter buttercream. The result is a tender, deeply flavored cake that stays moist for days.
Equipment
- Three 8-inch round cake pans
- Stand mixer with paddle attachment
- Parchment paper rounds
- Serrated Knife
- Offset spatula
- Cake turntable
Ingredients
Cake
- 3 cups all-purpose flour spoon and level (375g)
- 1 cup granulated sugar (200g)
- 2 cups packed dark brown sugar (400g)
- 2.5 teaspoons baking powder (10g)
- 2 teaspoons ground cinnamon (5g)
- 1 teaspoon fine salt (6g)
- 1 cup unsalted butter room temperature, 2 sticks (226g)
- 1 cup egg whites room temperature, or 7 large egg whites (240g)
- 1.5 cups buttermilk room temperature (360g)
- 2 tablespoons vegetable oil or canola oil (28g)
- 2 teaspoons vanilla extract or vanilla bean paste (8g)
Cookie Butter Frosting and Soak
- 3 cups unsalted butter room temperature, 6 sticks (678g)
- 1 tablespoon vanilla extract or vanilla bean paste (12g)
- 1.5 teaspoons fine salt (9g)
- 10 cups powdered sugar sift if lumpy, 1250g
- 0.75 cup heavy whipping cream room temperature, divided (1/2 cup for frosting, 1/4 cup for soak, 180g total)
- 2 cups cookie butter divided (1 cup for frosting, 1 cup for soak, 780g total)
- 12 Biscoff cookies cut into small pieces for topping
Instructions
- Preheat your oven to 350°F (177°C). Grease three 8-inch cake pans and line the bottoms with parchment paper rounds. Dust the sides with a little flour and tap out the excess.
- In a medium bowl, whisk together 3 cups all-purpose flour, 2½ tsp baking powder, 2 tsp cinnamon, and 1 tsp fine salt. Set aside.
- In the bowl of a stand mixer fitted with the paddle attachment, beat 1 cup (2 sticks) room temperature butter, 1 cup granulated sugar, and 2 cups packed brown sugar on medium-high speed for 3–4 minutes until light and fluffy. Scrape the bowl once or twice.
- Turn the mixer to low. Add 2 Tbsp oil, 2 tsp vanilla, and 1 cup room temperature egg whites in a slow, steady stream. Mix until just combined.
- Add the flour mixture in three additions, alternating with 1½ cups buttermilk, starting and ending with flour. Mix on low until a few streaks of flour remain, then fold by hand with a rubber spatula until just combined.
- Divide the batter evenly among the three pans (about 640g per pan). Bake for 22–27 minutes until the cakes spring back lightly and a toothpick inserted in the center comes out clean or with a few moist crumbs. Let cool in pans for 10 minutes, then turn out onto a wire rack to cool completely.
- Make the vanilla buttercream: In a clean mixer bowl with the paddle attachment, beat 3 cups (6 sticks) room temperature butter on medium speed for 2 minutes until smooth. Add 1 Tbsp vanilla and 1½ tsp salt. Gradually add 10 cups powdered sugar, one cup at a time, on low speed. Add ½ cup heavy cream and mix until incorporated, then whip on medium-high for 3–4 minutes until light and fluffy.
- Reserve about 1½ cups of the vanilla buttercream for another use (or eat it). To the remaining buttercream, add 1 cup cookie butter and mix until combined. In a small saucepan, warm the other 1 cup cookie butter with ¼ cup heavy cream over low heat, stirring until smooth and pourable — this is your soak and drip.
- Place one cooled cake layer on a serving plate. Use a pastry brush to generously soak it with the warm cookie butter mixture. Spread about ½ cup of cookie butter frosting over it. Repeat with the second and third layers. Apply a thin crumb coat to the entire cake and refrigerate for 20–30 minutes until set.
- Apply the final generous layer of cookie butter frosting. Top with crushed Biscoff cookie pieces and drizzle with the remaining cookie butter soak. Let the cake sit at room temperature for 30 minutes before slicing.
Notes
Storage: Store the assembled cake in an airtight container in the fridge for up to 5 days. Let sit at room temp 20–30 minutes before serving. Un-iced cake layers can be frozen tightly wrapped for up to 3 months.
Tips from testing: Room temperature ingredients are essential. Don't overmix the batter. The cookie butter soak is the hero. A crumb coat makes frosting easier.
Swaps: No buttermilk? Use 1½ cups whole milk + 1½ Tbsp lemon juice or vinegar. For spicier cake, add ½ tsp nutmeg and ¼ tsp cloves. Crunchy Biscoff spread works great for the soak but use smooth for frosting. Buttercream too thick? Add 1 Tbsp cream at a time.
Q&A: Why did my cake sink? Oven temperature or old baking powder. Can I use salted butter? Yes, omit added salt. Can I make a two-layer cake? Use two 9-inch pans and bake 25–30 min. Frosting curdled? Butter was too cold or warm; adjust with warm water bath or refrigeration.