Fold a 12-inch long strip of wax paper in half lengthwise. Coat an 8- inch loaf pan with cooking spray; place wax paper in pan, allowing long ends to extend over the long sides of the pan.
Arrange 12 cookies in prepared pan. Drizzle 1 1/2 tablespoons Kahlúa over cookies; set aside.
Beat 2 cups ice cream at high speed of a mixer 10 seconds or until smooth and softened. Spread ice cream evenly over Kahlúa-soaked cookies. Freeze 20 minutes.
Repeat layering procedure with cookies, Kahlúa, and remaining ice cream. Cover with plastic wrap, and freeze 8 to 24 hours.
Discard plastic wrap. Invert cake onto serving platter; remove wax paper. Freeze until ready to frost.
Fold instant coffee granules into whipped topping; spread mixture over top and sides of cake. Cut cake into 3/4-inch slices, and serve immediately.