Warm a demitasse cup with hot water, then dry it. Purge the group head and steam wand.
Dose 0.25 ounces finely ground espresso coffee into the portafilter, distribute evenly, and tamp firmly until level.
Lock in the portafilter and brew a single shot, aiming for about 1 ounce in 25–30 seconds; stop when the stream turns blond.
In a small pitcher, steam 0.25 cup whole milk to 140–150°F for 15–30 seconds, creating silky microfoam with fine, glossy bubbles; tap and swirl the pitcher to settle the foam.
Spoon 1–2 teaspoons of the foam to lightly “stain” the center of the espresso. Serve immediately.