Crush the cookies in a large plastic bag using a rolling pin, or use a food processor to crush the cookies. Mix crushed cookies with melted butter. Measure 3/4 cup and set aside. Press remaining cookie mixture evenly into an ungreased 9 x 13-inch pan, to form the bottom layer of the cake.

Spread softened ice cream over cookie layer. Spread whipped topping over ice cream. Sprinkle pecans over whipped topping. Drizzle chocolate syrup over all. Sprinkle reserved 3/4 cup cookie mixture over syrup. Freeze.

After cake has been in freezer 2 to 3 hours and is beginning to firm up, cover pan with foil. For best texture, assemble and freeze cake 2 days in advance. To serve, simply cut into squares and enjoy.