Cookie Butter Batter

• 2 1/2 cups + 2 tbsp cake flour
• 1 1/2 cups granulated sugar
• 1 tbsp baking powder
• 1/2 tsp fine sea salt
• 6 1/2 tbsp unsalted butter, room temperature and cubed
• 1/3 cup cookie butter
• 1 cup sour cream, room temperature
• 1/4 cup vegetable or canola oil
• 1 cup whole milk, room temperature
• 2 large eggs, room temperature
• 1 1/2 tsp vanilla extract
• 3 tbsp melted cookie butter for swirling

Biscoff Buttercream

• 1 1/2 cups unsalted butter, softened
• 2/3 cup cookie butter
• 1 3/4 cup powdered sugar
• 2 tbsp heavy cream
• 1/2 tsp vanilla extract
• 1/2 cup Biscoff cookie crumbs for the center of the cake and sides
• 1/2 cup cookie butter for the layers and top of the cake