Combine crushed oreos and 1/3 c. softened butter in a medium mixing bowl. Press into the bottom of an ungreased square baking pan and refrigerate until firm.

In a separate bowl, combine powdered sugar, 1/3 c. softened butter, orange zest, orange extract, and milk. Mix at high speed until mixture resembles frosting.

Spread powdered sugar mixture evenly over chilled crust.

Top with mini chocolate chips and drizzle with melted chocolate.

Refrigerate until firm, about 2 hours.

Store in refrigerator.