Prepare a 13x9 pan by spraying lightly with cooking spray or buttering lightly. Set aside.
In large saucepan over medium-low heat, combine butter and condensed milk and stir until butter is completely melted.
Add marshmallows and stir until they are completely melted.
Reduce heat to very low and stir in vanilla extract.
Stir in cereal and combine well. Before mixture is completely mixed, remove pan from heat, scatter in cookie crumbs and stir until they are distributed through mixture.
Spread into prepared pan.
Frosting
Prepare the frosting by combining white chocolate and condensed milk in small saucepan over low heat until chocolate chips are completely melted.
Once melted, stir in vanilla extract.
Remove from heat and immediately spread or drizzle over rice krispie treats.
Sprinkle with crushed cookies
Allow to cool at least 30 minutes before cutting and serving.