Butter the bottom and sides of two 9-inch cake pans, and preheat your oven to 350 degrees Fahrenheit (177 degrees Celsius).
In a stand mixer, beat the butter until light and fluffy.
Next, add the dry ingredients to the butter and incorporate well.
Add the wet ingredients to the mixer and combine.
Fold in the chopped Oreos by hand.
Divide the cake batter evenly into the two cake pans, and bake for 20-25 minutes, until a toothpick comes out clean.
While the cake is baking, prepare the buttercream. Beat the butter until it is light and fluffy.
Add the confectioners' sugar and cream, and mix together.
Reserve about 1 ½ cups of the white buttercream separately for decorating the top and piping on the bottom.
Once a portion has been removed, add the finely crushed Oreos to the rest of the buttercream and mix together.
Once the cakes have baked and cooled to room temperature, place one layer of cake onto your stand and add the Oreo buttercream on top; this will be the middle of the cake.
After adding a layer of buttercream, flip the second layer upside down so that the top of the cake is a smooth, flat surface, and cover the entire cake with the Oreo buttercream.
Finally, use the white buttercream and whole Oreos you set aside to decorate your cake and enjoy!