In a small saucepan over medium heat, combine the brown sugar, 1 teaspoon pumpkin pie spice, and 1/2 cup water. Stir until the sugar is dissolved and bring it to a boil. Remove from heat and cool for 30 minutes. Syrup can be stored in the refrigerator for up to 2 weeks.
Mix together the granulated sugar and remaining 1 teaspoon pumpkin pie spice and put it onto a shallow plate. Pour 2 tablespoons of the simple syrup onto a plate. Dip the rims of 4 martini glasses into the syrup, and then in the spiced sugar. Set aside.
In a large measuring cup, combine the half-and-half, pumpkin puree, vanilla, and half the simple syrup and whisk until well blended. Pour in to a pitcher filled with ice. If using the vodka, add it to the pitcher before serving and stir. Pour into the prepared glasses. Top with sparkling water.
Recipe courtesy of Sandra Lee