Step 1. Prepare the Cake Batter:

• Preheat your oven to 350°F (175°C). Grease and flour an 11x7 or 9x9 inch cake pan, or line it with parchment paper.
• In a medium-sized bowl, combine the flour, baking powder, and salt. Whisk together until well mixed.
• In a large mixing bowl or using a stand mixer fitted with the paddle attachment, beat the butter, granulated sugar, and cookie butter until light and fluffy, about 2-3 minutes.
• Add the eggs one at a time, ensuring to beat well after each addition. Then mix in the vanilla extract.
• Gradually add the dry ingredients alternately with the buttermilk, beginning and ending with the flour mixture. Mix until just combined.
• Carefully pour the batter into the prepared cake pan, then use a spatula to gently smooth the top until it's even.

Step 2. Bake the Cake:

• Bake the cake in the preheated oven for approximately 40 minutes, or until a toothpick inserted into the center comes out clean.
• After baking, remove the cake from the oven and allow it to cool completely in the pan before frosting.

Step 3. Make the Cookie Butter Frosting:

• In a large mixing bowl or using a stand mixer, beat the room temperature butter and cookie butter together until smooth, about 1 minute.
• Gradually add the powdered sugar, mixing on medium speed until smooth and creamy.
• Slowly add the heavy cream or milk, a tablespoon at a time, until the frosting reaches your desired consistency. Beat the frosting until light and fluffy, about 3-4 minutes.

Step 4. Assemble the cake

• Ensure that your Biscoff cake layers have cooled completely.
• If the cake layers have domed during baking, you may want to level them using a serrated knife or cake leveler to ensure a flat surface for stacking.
• Choose a flat serving plate or cake stand to assemble your cake on.
• Place the first cake layer on the serving plate, with the flat side facing up.
• Spoon a generous amount of cookie butter frosting onto the top of the first cake layer.
• Use an offset spatula or the back of a spoon to spread the frosting evenly over the surface of the cake layer, ensuring it reaches the edges.
• Carefully place the second cake layer on top of the frosting layer.
• Press down gently to secure the layers together.
• If desired, you can apply a thin layer of frosting around the entire cake to seal in any crumbs. This step helps to create a smooth final coat of frosting.
• Once applied, refrigerate the cake for about 30 minutes to allow the crumb coat to set before proceeding.

Step 5. Frost the Cake:

• Once the crumb coat has set (if applied), generously frost the top and sides of the cake with the remaining cookie butter frosting.
• Spread the frosting evenly over the cake with the spatula. Start from the top and move downwards, making sure to smooth the sides as you go.
• For a smoother finish, you can use a bench scraper or the edge of a straight spatula to smooth the frosting on the sides of the cake.
• Garnish the top of the cake with Biscoff cookie crumbs, drizzles of cookie butter, or whole Biscoff cookies for an extra decorative touch.
• If you have time, refrigerate the assembled cake for about 1 hour before serving to allow the frosting to set and the flavors to meld together.

Step 6. Serve and Enjoy:

• Once chilled (if desired), slice the cake into portions and serve.

Enjoy your delicious Biscoff Cookie Butter Cake Recipe with Cookie Butter Frosting.