Break cookies into large pieces and place into a food processor. Puree until cookies are finely ground and no chunks remain.
8 Oreo cookies
In a mixing bowl mix butter with the whisk attachment on your mixer. Mix until smooth and creamy, about 2-3 minutes.
1 cup butter
Add powdered sugar and mix until well incorporated. Mixture will be very thick.
2 ½ cups powdered sugar
Mix in vanilla and then add the cream. Mix until smooth. Add a bit more cream for a creamier consitency.
2 teaspoons vanilla, 2-3 tablespoons cream or milk
Fold in ground cookie crumbs with a large silcone spatula or heavy duty spoon.
Notes
Make certain butter is soft, but not melted
Use the whisk attachment to mix buttercream
If powdered sugar is lumpy, be certain to sift through a fine mesh sieve
Add a bit of additional cream to make the frosting the desired consistency
Frosting can be covered and refrigerated until needed. Make certain you allow frosting to return to room temperature before spreading or piping.
If piping, make certain to fully crush cookies. Any chunks will clog your piping bag making it impossible to pipe the frosting.
If spreading frosting with a knife, larger chunks of cookies may be used
If piping, use a coupler along with a large open tip to make certain the frosting flows easily. If the tip does become clogged, simply remove the coupler and tip and then remove the blockage. Replace tip and continue piping.
Small Oreo cookies can be used as a garnish or you can sprinkle a bit of additional cookie crumbs over the top of the frosting.