Step 1: Prepare Your Ingredients. Gather all your ingredients and ensure that your Cool Whip is thawed for easier mixing.
Step 2: Mix the Base. In a large mixing bowl, combine the condensed milk, chocolate milk, and vanilla extract. Stir until well mixed.
Step 3: Add Cool Whip. Gently fold in the Cool Whip to the chocolate milk mixture. This will give your Frosty that signature creamy texture.
Step 4: Blend It Up. Pour the mixture into your blender and blend on high speed until smooth and creamy, about 30 seconds to 1 minute.
Step 5: Serve Immediately or Chill. You can serve your Wendys Frosty immediately for a soft-serve texture, or if you prefer it a bit firmer, pour it into a container and freeze for about 2 hours before serving.