Combine 1 cup blueberries, 1 tbsp sugar and 2 tbsp water in a small saucepan over medium heat. Cook, stirring, until the berries soften and release juices, about 4–6 minutes.

Blend & strain

Carefully transfer the cooked blueberries to a blender or use an immersion blender; add 1/2 tsp fresh lemon juice and blend until smooth. Strain through a fine mesh sieve into a bowl to remove skins and seeds, pressing with the back of a spoon. Yield should be about 4–6 oz. Cool to room temperature before using.

Shortbread rim

Pulse 3 shortbread cookies in a food processor or place in a zip-top bag and crush with a rolling pin until they form fine crumbs. Stir the crumbs with 1 tsp sugar and 1/2 tsp grated lemon zest to combine.

Spread the shortbread mixture on a small plate. Brush 1 tbsp lemon curd around the outside rim of a chilled margarita or coupe glass, then press the sticky rim into the shortbread crumb mixture to coat evenly. Set glass aside.

Cocktail assembly

Add 2 oz Jose Cuervo Tradicional, 0.75 oz triple sec, 1 oz fresh lemon juice, 1 oz cooled blueberry purée, 0.5 oz lemon curd, 0.5 oz Madagascar vanilla syrup and 1 cup ice to a cocktail shaker. Note: If your lemon curd is very thick, soften it slightly by whisking with the vanilla syrup before adding to the shaker so it integrates smoothly.

Dry-shake (no ice) vigorously for 10–15 seconds to begin emulsifying the lemon curd, then add ice and shake hard for 12–15 seconds until well-chilled and slightly frothy.

Double-strain the cocktail into the prepared shortbread-rimmed glass. If you prefer a slushy texture, serve over fresh crushed ice.

Garnish with 4–6 fresh blueberries threaded on a cocktail pick and a thin lemon wheel or twist on the rim. Serve immediately.