Pour the cold brew over ice.
Mix milk, sugar, and vanilla extract in a container.
Froth your milk using your preferred method:
Method 1: Use a handheld milk frother to froth for about 30 seconds, or until it doubles in size.
Method 2: Use a food processor or blender. Blend for 1 - 2 minutes until foamy.
Method 3: Use a mason jar. Pour milk mixture into a mason jar and tightly secure the lid on. Shake vigorously for about 2 minutes, or until foamy and doubled in size.
Top iced coffee with foam and enjoy.