It takes 15 minutes to bake, 30 minutes for the white icing to harden and 30 minutes for the chocolate icing to harden so it takes 15+30+30 = <<15+30+30=75>>75 minutes
Every hour has 60 minutes and it takes her 2 hours so it takes 60*2 = <<60*2=120>>120 minutes to make the cookies
It takes 120 minutes to make the cookies from start to finish and she spends 75 minutes baking and hardening icing so it takes her 120-75=<<120-75=45>>45 minutes to make the batter and cool the cookies
#### 45