Preheat the oven to 325 degrees F. Using 3, 8 inch cake pans, spray the bottom of the cake pan with cooking spray, line with parchment paper, and spray again. Set aside.

Place the Biscoff cookies in a blender and blend until the cookies are finely ground into a fine crumb.

In a medium-sized bowl, whisk together the Biscoff crumbs, all-purpose flour, baking powder, baking soda, and salt until evenly combined.

In the bowl of a stand mixer fitted the paddle attachment, cream the butter, brown sugar, and oil on medium speed until light and fluffy, about 5 minutes. The mixture will start looking light in color.

Add the eggs, one at a time, beating on medium speed for 30 second after each addition. Add the vanilla and mix on the lowest speed, just until combined.

With the mixer on the lowest speed, add ⅓ of the dry ingredients and half of the buttermilk. Mix just until combined. Repeat this step. Add the rest of the flour mixture and continue to mix on the lowest speed until the flour and the buttermilk have all been incorporated. With a rubber spatula scrape down the sides and bottom of the bowl and slowly mix by hand.

After they are out of the oven, I let mine cool for 15 minutes. Then I transfer them onto a wire rack to finish cooling. Let them come to room temperature before wrapping them in plastic wrap and freezing or refrigerating.

In a microwave safe bowl, heat the chocolate for 30 seconds, stir, heat for 30 more seconds, and set aside. The chocolate will not be melted all the way, but this will help it melt quicker when you add the cream.

In another microwave proof bowl, heat the cream until nearly boiling. Make sure it doesn’t boil over. Pour the hot cream over the slightly warm chocolate chips. Let it sit for 2 minutes and then stir. Set aside.

In the bowl of a stand mixer fitted with the paddle attachment, beat the butter for about 2 minutes on medium-high speed.

Add the chocolate/cream mixture. Scrape down the sides and bottom of the bowl with a rubber spatula and beat for 1 more minute.

Add the powdered sugar, vanilla, and salt. Mix on low until combined, then turn the mixer to medium high and beat for 3 minutes.

With a wooden spoon or rubber spatula, beat by hand to mix out any air pockets.

Level the cakes if needed. I like to frost my cake chilled or frozen.

Place the first cake layer on a cake board, top side up. Gently and evenly spread about a cup of the buttercream over the cake layer.

Repeat this step with the second cake layer.

Place your final cake layer, top side down.

Apply a thin layer of the chocolate buttercream around the entire cake and freeze the cake for 10 to 15 minutes.

Once the crumb coat is set, finish frosting and decorating the cake with the remaining chocolate buttercream. Serve at room temperature.