Prepare the Glasses: Begin by prepping your margarita glasses. Take a lime wedge and run it around the rim of each glass. Then, dip the rim into a plate filled with coarse sea salt, ensuring an even coating for a delightful salty contrast.
Mix the Juices: In a large pitcher, combine the freshly squeezed lime juice and orange juice. Add the agave syrup and stir vigorously until the syrup is fully dissolved, ensuring a balanced sweetness.
Incorporate the Spices: Sprinkle in the ground cinnamon, nutmeg, allspice, and optional cayenne pepper into the juice mixture. Stir well to evenly distribute the spices throughout the liquid, creating a beautifully aromatic blend.
Add Sparkle: Just before you're ready to serve, gently fold in the sparkling water to the pitcher. This will ensure your margarita has a refreshing fizz that brightens the flavors.
Serve Over Ice: Fill each rimmed glass with ice. Carefully pour the spiced margarita mixture over the ice, allowing the frothy top to form as the bubbly water interacts.
Garnish and Enjoy: For a festive presentation, garnish each glass with a slice of lime placed on the rim and a cinnamon stick nestled inside.
Notes
Consider serving the margaritas on a decorative tray adorned with holiday-themed accents.