Let roll of cookie dough stand at room temperature 10 minutes to soften
Spray bottom only of 13×9-inch pan.
Stir butter, 1 1/2 cups of the cracker crumbs and half of the toffee bits. Press mixture evenly in bottom of pan. Refrigerate about 15 minutes or until firm.
In 2-quart saucepan, heat chocolate chips, sweetened condensed milk and butter over medium heat, stirring frequently, until chips are melted and mixture is smooth. Remove from heat; stir in vanilla. Spread mixture over cracker crust.
Break up cookie dough. Mix in remaining 1/2 cup cracker until well blended. Crumble mixture evenly over chocolate layer. Sprinkle with remaining 3/4 cup toffee bits.
Bake 25 to 35 minutes or until golden brown. Cool completely, about 2 hours.