Preheat your oven to 350°F (175°C). Line three 8-inch cake pans with parchment paper and grease them. This step ensures your cake doesn’t stick and slides out effortlessly when baked.

Combine all-purpose flour, cinnamon, baking powder, and salt in a large bowl. Using a mixer, gradually mix in the butter until the mixture becomes crumbly. It’s the base for incredibly tender cake layers!

Whisk in the egg whites, followed by buttermilk and vanilla extract. Mix until smooth and creamy. If you’re using a hand mixer, be sure to scrape down the sides for an even consistency.

Divide the batter evenly into the prepared pans. Bake for about 33-35 minutes, rotating the pans halfway through for even cooking. Once baked, allow the layers to cool before frosting.

While the cake cools, whip unsalted butter, powdered sugar, and heavy cream to make vanilla frosting. Add cookie butter to a portion of the frosting for a flavorful twist.

Layer the cakes with alternating vanilla and cookie butter frosting. Drizzle warm cookie butter between layers for extra flavor. Finish by pressing crushed Biscoff cookies onto the sides and piping details on top.

Refrigerate the cake for at least 20 minutes before serving. This allows the flavors to meld and the frosting to set perfectly. It’s worth the short wait!