combine the butter and sugar in a bowl and mix together. I recommend using an electric mixer
add in the eggs, cinnamon, and vanilla extract and combine until the eggs fluff up
finally add in the flour and baking powder and once your batter forms, add in the Biscoff cookie chunks gradually until everything is well combined
Separate batter equally into two small baking pans if you want a two layered cake, or one larger pan if you want a single layered cake
Bake at 350 degrees for 25-30 minutes
While the cakes are in the oven start your frosting by simply adding all the frosting ingredients into a bowl and mixing until everything is smooth and well combined.
How to Assemble
If you chose to do a two layer case, first take the bottom layer and shave off the top part to make it relatively flat
Then, add a thin layer of icing to the flat surface
Add on the top layer and cover the entire top surface with frosting. Start with a thinner layer to male sure you have enough for the sides
Cover the sides on the entire cake with a very thin layer of frosting, then crush up Biscoff cookies and cover the sides with the crumbs. I recommend just using your hands
With whatever remaining frosting you have, add it to the top