Make cake according to package directions. Place in a sprayed (greased) 13x9 pan. Bake according to package directions. Remove from oven and with a fork poke holes all over the top of the cake.
In a pyrex glass measuring cup heat water up in microwave until boiling. Pour in jello and stir until jello is dissolved. Pour evenly over hot cake. Place cake in fridge to cool uncovered (be careful pan is still really hot, I also put a towel on the fridge shelf to protect it. I usually let the cake sit for about 2 hours or until completely cool.
Remove cake from oven and frost with entire container of cool whip. Mix sliced strawberries with sugar and sprikle them over the cool whip mixture covering top of cake. Place back in fridge for around 30 minutes. Remove cake from fridge and cut into squares and serve. Cover and refridgerate any leftovers.... enjoy