Vanilla Biscoff Cake

1. Preheat the oven to 325°F (165°C). Line the bottoms of three 6-inch (15 cm) cake pans with parchment paper.
2. In a bowl, whisk together the cake flour, baking powder, baking soda, salt, and finely crushed Biscoff cookies.
3. In a large mixing bowl, beat the softened butter and granulated sugar for about 3 minutes until light and creamy.
4. Add the eggs and vanilla extract, mixing until smooth and well combined.
5. Mix in the buttermilk and Biscoff cookie butter spread until the batter looks smooth.
6. Add the dry ingredients and mix on low speed just until the batter is smooth and fully combined.
7. Divide the batter evenly between the prepared pans.
8. Bake for 35 to 40 minutes, until the cakes are golden and a toothpick inserted in the center comes out clean.
9. Let the cakes cool for 10 minutes in the pans, then transfer to a wire rack and cool completely before frosting.

Cookie Butter Swiss Meringue Buttercream

1. Place the egg whites and granulated sugar in a heatproof bowl set over a saucepan of gently simmering water.
2. Whisk constantly until the mixture reaches about 65–70°C (150–160°F) and the sugar is completely dissolved.
3. Transfer the mixture to the bowl of a stand mixer fitted with the whisk attachment.
4. Whip on high speed for about 10–15 minutes until the meringue is glossy, thick, and completely cooled.
5. Reduce the mixer speed to medium and add the softened butter a few pieces at a time until incorporated.
6. Increase the speed and whip until the buttercream becomes smooth and fluffy. The mixture may look curdled or runny at first but will come together.
7. Add the vanilla extract and Biscoff spread and mix until fully combined.
8. Switch to the paddle attachment and mix on low speed for 1–2 minutes to remove excess air bubbles.

Cookie Butter Mascarpone Whipped Cream

1. Place the cold mascarpone, cold heavy cream, powdered sugar, vanilla extract, and Biscoff spread in a large mixing bowl.
2. If the Biscoff spread is very firm, warm it slightly for a few seconds so it blends easily.
3. Whip on low to medium speed until the frosting becomes thick, smooth, and holds soft peaks.
4. Use immediately or refrigerate until ready to assemble the cake.

Assembly & Decoration

1. Trim the tops of the cake layers if needed to level them.
2. Place the first cake layer on a cake stand or turntable. Pipe a ring of buttercream around the edge, then fill the center with mascarpone frosting, crushed Biscoff cookies, and a spoonful of cookie butter spread.
3. Repeat with the remaining layers.
4. Apply a thin crumb coat of buttercream over the entire cake and refrigerate for about 20 minutes.
5. Spread a smooth final layer of buttercream over the chilled cake.
6. Warm the cookie butter slightly and drizzle it over the top to create the drip.
7. Finish by piping buttercream swirls on top and decorating with crushed Biscoff cookies.