Melt the butter in the microwave or on the stove. Mix crushed cookies with the melted butter. Press half of the mixture in the bottom of a pie plate and chill in the fridge. Set aside the rest of the cookie mixture.
Melt the remaining butter with the chocolate in a saucepan. Remove from heat and stir in the sugar. Gradually pour in the evaporated milk, stirring while pouring. Stir in the vanilla extract and set aside.
Remove the crust from the fridge. Top the crust with coffee ice cream. Top with the remaining crushed Oreos and place in the freezer. Once the ice cream has firmed up in the freezer, spread over the fudge and return to the freezer.