Directions To the can of vanilla frosting, add 6 to 8 drops of coloring and stir until frosting is completely blue. Use a small spatula or a butter knife to spread blue food coloring around the rim of a tall glass. Add crushed cookies to a shallow plate, then roll the frosted rims in crushed cookies until blue frosting is almost completely covered. Make Cookie Monster cookies: Spread blue frosting onto two cookies then place two candy eyes onto each. Pour into glasses then dollop with Cool Whip and garnish with a cookie.