In a small saucepan, combine fresh blueberries, granulated sugar, and lemon juice over medium heat. Cook for about 8 minutes until blueberries soften and the mixture thickens.

In a mixing bowl, whisk together mascarpone cheese, heavy cream, powdered sugar, and vanilla extract until smooth and fluffy (about 2-3 minutes with an electric mixer).

Once cooled, gently fold the blueberry compote into the mascarpone mixture. Reserve some compote for garnish.

In a shallow dish, mix cooled coffee with blueberry liqueur. Quickly dip ladyfingers in the coffee, then arrange in a single layer in an 8x8-inch pan.

Spread half of the blueberry-mascarpone mixture over the ladyfingers, then add another layer of coffee-dipped ladyfingers, and finish with the remaining mixture.

Cover with plastic wrap and refrigerate for at least 4 hours or overnight to allow the flavors to meld.

Before serving, drizzle reserved blueberry compote and sprinkle with lemon zest. Garnish with mint leaves for a fresh touch.