In a mixing glass, stir all the ingredients together, except for the cava and lemon twist. Strain into a chilled coupe glass and top with the cava. Garnish with a lemon twist and serve.
*To make the cinnamon syrup, combine ½ cup of granulated sugar with ½ cup of water and ½ teaspoon of ground cinnamon, and bring to a boil in a small saucepan. Cook until the sugar has dissolved, then let cool completely.