Move oven rack to lowest position. Heat oven to 180°C.
Make cake mix as directed on box, using water, oil and eggs. Carefully fold crushed cookies into batter. Pour into ungreased tube pan.
Bake 35 to 45 minutes or until top is dark golden brown. Let stand 2 hours or until completely cool. Remove from pan by gently pulling cake away from side of pan, using fingers, taking care not to tear cake (cake will spring back to original shape.)
Beat frosting and boiling water on low speed for 30 seconds then on high speed 5 to 7 minutes, scraping bowl occasionally, until stiff peaks form.
Frost cake, and garnish with sandwich cookie halves.