Step 1: Wash and hull the fresh strawberries. If using larger berries, quarter them.
Step 2: In a blender or food processor, combine the hulled strawberries, 1 tablespoon of granulated sugar, and 1 tablespoon of water. Blend until completely smooth.
Step 3: (Optional) For a silky-smooth foam, pass the strawberry puree through a fine-mesh sieve into a separate bowl, pressing with the back of a spoon to extract all liquid. Discard any solids/seeds.
Step 4: In a cold mixing bowl, combine the very cold heavy cream, 2 tablespoons of the prepared strawberry puree, and 1/2 teaspoon of vanilla extract (if using).
Step 5: Using an electric hand mixer, stand mixer with a whisk attachment, or a milk frother, whisk the mixture on medium-high speed until the cream thickens and soft peaks form (2-4 minutes). Be careful not to over-whisk into stiff whipped cream.
Step 6: Taste the cold foam and add a tiny pinch more sugar if desired, then whisk briefly to combine.
Step 7: To serve, pour your favorite iced beverage into a glass and gently spoon the strawberry cold foam over the top. Garnish as desired.