[header] How to make rainbow chocolate chip cookies [title] Prepare the oven and tray. [step] Preheat the oven to 350 degrees fahrenheit or 176 degrees celsius. Cover a baking tray with parchment paper or spray non-stick greasing spray on it. 
[title] Combine the flour, baking soda, and cornstarch with a whisk. [step] Stir until the dry ingredients are mixed properly.