Prepare the strawberry syrup: In a small saucepan, combine the sliced strawberries and granulated sugar. Cook over medium heat for 5-7 minutes, stirring occasionally, until the strawberries soften and release their juices. Remove from heat and strain the mixture to remove the solids, leaving just the syrup. Allow it to cool to room temperature.

1. Whip the cream: In a large mixing bowl, beat the heavy cream until stiff peaks form, using an electric mixer or whisk.
2. Make the mascarpone filling: In a separate bowl, whisk together the softened mascarpone cheese, powdered sugar, and vanilla extract until smooth and creamy.
3. Fold in the whipped cream: Gently fold the whipped cream into the mascarpone mixture until well combined, creating a light and fluffy filling.
4. Assemble the tiramisu: Dip each ladyfinger into the cooled strawberry syrup for about 1-2 seconds (do not soak too long). Arrange a layer of soaked ladyfingers at the bottom of a 9×9-inch baking dish or serving trifle dish. Spread half of the mascarpone cream mixture over the ladyfingers.
5. Add strawberries: Layer half of the fresh sliced strawberries over the mascarpone cream.
6. Repeat layers: Dip the remaining ladyfingers in the strawberry syrup and layer them over the strawberries. Spread the remaining mascarpone cream on top and smooth it out with a spatula.
7. Chill: Cover the tiramisu with plastic wrap and refrigerate for at least 4 hours, or overnight for best results. This allows the flavors to meld together and the tiramisu to set.
8. Serve: Before serving, garnish with extra fresh strawberries and mint leaves for a beautiful presentation. Serve chilled.