Preheat oven to 350°F. Spray three 8 inch cake pans with baking nonstick spray. Place an 8 inch parchment paper on the bottom. Spray again.

Using a blender, blend 15 biscoff cookies into a fine crumb. In a mixing bowl, mix the flour, biscoff crumbs, baking powder, and salt.

Using a mixer, beat the butter, oil, and sugar. Beat on high for 3 minutes until very light and fluffy. Add in vanilla, sour cream, and eggs. Beat on high for 2 minutes until fluffy.

Add in ⅓rd of the dry ingredients and half of the buttermilk. Mix until almost combined. Add in another ⅓rd of the dry ingredients and the rest of the buttermilk. Finish with the rest of the dry ingredients. Take bowl off the mixer and scrape the bowl.

Pour the batter evenly through the three cake pans. Bake for 28-35 minutes until a toothpick inserted comes out clean.

Let the cakes sit for 10 minutes in the hot pans. Transfer the cakes to a cooling rack. Let them cool completely before decorating.

Using a mixer, beat the cream cheese on high for 1 minute. Add in the cookie butter and beat until smooth. Add in sifted powdered sugar and mix. It will be crumbly at first but will smooth out. Mix in the vanilla.

Freeze a metal bowl and whisk attachments for 10 minutes. Pour heavy cream into a cold bowl. Beat on high until stiff peaks form.

Fold in the whipped cream into the cookie butter. Fold gently to not knock out any air. Fold until smooth. Chill for at least an hour or overnight.

Pull the butter out for 30 minutes to get slightly cold. Sift the powdered sugar while you wait.

Using a mixer, beat butter on high for 1 minute. Scrape the bowl and add in the cookie butter. Beat on high for 2 minutes. Scrape the bowl.

Slowly add in the powdered sugar. Add in heavy cream, vanilla, and salt. Mix on low until combined. Switch to high and beat for 1 minute.

Place cake layers in the freezer for 30 minutes to get cold.

Place a small amount of frosting on the board you are decorating on to lock the cake in place.

Place the 1st layer of cake down. Spread a ½ cup of frosting over the cake. Pipe a border of frosting around the edge of the cake. Spread half of the cookie butter filling on top of the cake. Top with half of the chopped cookies. Repeat with the second layer.

Place last layer of cake bottom side up to give the flattest surface on top of the cake. Freeze the cake for 10 minutes to chill the filling.

Frost the cake with a light layer of frosting. Freeze for 15 minutes to seal the crumbs. Frost the rest of the cake.

Melt the cookie butter in the microwave. Let it cool slightly. Freeze the cake for 10 minutes. Pour the cookie butter over the cake and let it drip down the sides of the cake. Top with biscoff cookies.