Cookie butter can be quite thick straight from the jar. If needed, warm it in the microwave for about 5 to 10 seconds until it becomes easier to mix. You don't want it hot or melted completely. Just soften it enough so it blends smoothly with the milk and cream. This small step prevents lumps and creates a silky texture in the finished foam.
Add the milk, heavy cream, softened cookie butter, and vanilla extract to a frothing cup or small glass. Make sure the ingredients are well distributed before frothing. This helps create an even flavor throughout the foam. Using cold dairy ingredients will produce the best texture and volume.
Insert the handheld frother into the mixture and froth for about 20 to 30 seconds. The mixture should become light, thick, and airy while remaining pourable. Stop frothing once soft peaks begin to form. Avoid over-frothing because the foam can become too stiff and difficult to pour over coffee.
Fill a serving glass with ice and pour in your favorite cold brew, iced coffee, or iced latte. Leave some room at the top of the glass for the cold foam. This creates the perfect layered presentation. The cold foam will slowly mix into the coffee as you drink, creating amazing flavor in every sip.
Slowly pour the freshly made cold foam over the coffee. Allow it to settle naturally on top for a beautiful café-style appearance. The foam should float above the coffee layer. For an extra-special touch, sprinkle crushed cookie crumbs over the foam before serving.
Serve the drink immediately while the foam is fresh and fluffy. Sip directly through the foam layer to enjoy the creamy cookie butter flavor first. Stir the foam into the coffee if you prefer a sweeter and richer drink experience.