Place 3 fresh blackberries in a mixing glass or shaker. Add the lemon juice and simple syrup. Use a muddler to crush the berries until they release juice and are partially broken down (about 8–10 firm presses).

Combine spirits

Add the gin, blackberry liqueur, and dry vermouth to the muddled blackberry mixture. Add the optional activated charcoal syrup or a very small drop of black food coloring if you want the deep midnight color. Add a single dash of Angostura bitters.

Shake & dilute

Add plenty of ice (cubed) to the shaker — enough to fill about two-thirds. Shake vigorously for 12–15 seconds until well chilled and slightly diluted. If you prefer a more clarified drink, double-strain through a fine mesh into the serving glass to remove seeds and pulp.

Effervescence & finish

Fill a chilled coupe or Nick & Nora glass with one large ice cube or, for a colder presentation, with crushed ice. Strain the shaken mixture into the glass. Top gently with 2 tablespoons chilled sparkling water or prosecco to lift the aromatics and add effervescence.

Give the drink a gentle stir (1–2 rotations) to combine without flattening the bubbles.

Express the lemon peel over the drink by twisting it skin-side down to release oils, then rim the glass with the peel and drop it in as garnish. Optionally, spear one muddled blackberry on a small pick and rest across the rim.

Serve

Serve immediately while effervescent. Advise guests to sip slowly to enjoy the layered fruit, herbal, and bitter notes that evoke the cocktail's 'Midnight Muse' character.