How to Make It
Combine the apple cider, bourbon, simple syrup, and lemon juice in a 9-inch by 13-inch pan (preferably metal or glass). Freeze mixture, uncovered, for 4 hours. Use the tines of a fork to stir the mixture, scraping up and dispersing any icy bits. Return the pan to the freezer and continue to freeze, stirring every few hours, until the mixture is completely frozen and similar in texture to shaved ice. Cover pan in plastic wrap and keep frozen until ready to serve.
To serve, break up any larger pieces of ice that have formed and spoon the mixture into lowball or punch glasses. Top with an equal amount of dry cider and garnish with apple slices.
To make the brown sugar-cinnamon simple syrup:
Combine ¾ cup light brown sugar, ¾ cup water, and 1 teaspoon ground cinnamon in a medium saucepan. Bring to a simmer and stir to dissolve sugar. Remove pan from heat and cool completely. Refrigerate syrup in a covered container for up to 2 weeks. Makes ¾ cup.