Combine hibiscus flowers, 1/3 cup sugar, cinnamon sticks, and 2 cups water in a medium saucepan.

Cover and bring to a boil over medium heat.

Reduce heat and simmer for 5 minutes.

Remove from heat and let the mixture infuse, covered, for 20 minutes.

In a blender, puree halved strawberries with remaining 1/3 cup sugar and 2 cups cold water.

Strain the strawberry puree into a metal bowl and stir in lemon juice.

Set the bowl of strawberry puree in a larger bowl filled with ice and water until cold.

Strain the hibiscus infusion into another metal bowl and set in a bowl of ice and water until cold.

Combine the hibiscus infusion and berry puree in a pitcher.

Fill glasses with ice.

Add 1 1/2 oz of vodka to each glass, if desired.

Pour about 3/4 cup of the berry cooler into each glass.

Stir in a splash of sparkling water.

Top with quartered berries and mint sprigs.