In a medium saucepan, combine the sugar and cornstarch. Stir in water and lemon juice. Add frozen blueberries and stir to combine. Bring to a boil over medium-high heat, stirring frequently. Reduce to a simmer and cook for an additional 3-5 minutes, stirring often, until mixture is thickened. Cool completely.
In a medium bowl, beat heavy cream with an electric mixer until stiff peaks form. In a separate bowl, beat cream cheese, vanilla and sugar until smooth and fluffy. Fold in whipped cream.
Cut the pound cake into small squares. Divide half of the cake between 6-8 small cups or parfait glasses. Pipe or spoon half of the cheesecake filling over the cake. Top with a few spoonfuls of blueberry sauce. Repeat once, ending with blueberry sauce. Garnish with fresh mint before serving, if desired.