Combine shortbread cookie crumbs and butter; press firmly in bottom of a greased 9" springform pan. Bake at 350° for 8 to 10 minutes or just until toasted. Sprinkle crushed toffee bars over crust while crust is still warm. Cool completely.
Spread coffee ice cream over candy. Cover and freeze 30 minutes or until firm. Spread coconut-pecan frosting over ice cream. Cover and freeze several hours or until firm.
Remove pie from freezer, and let stand 5 minutes at room temperature. Remove sides of pan before serving. Garnish, if desired.