In a tall glass or frothing pitcher, combine the heavy whipping cream, milk, powdered peanut butter, maple syrup, and vanilla extract.
Submerge a handheld milk frother into the mixture and aerate for 30 to 45 seconds until the volume has nearly doubled and the consistency is thick and stable.
Fill a separate 16-ounce serving glass to the brim with ice cubes.
Pour the cold brew coffee over the ice, leaving approximately 1.5 inches of space at the top of the glass.
Gently pour the prepared peanut butter cold foam over the coffee so it layers on top and begins to cascade slowly into the brew.
Serve immediately with a straw or enjoy directly from the glass to experience the contrast between the foam and coffee.