In a medium bowl, mix sliced strawberries with granulated sugar and lemon juice. Let sit for 10–15 minutes until juicy.
In a large bowl, beat heavy cream until soft peaks form. Add powdered sugar and vanilla extract, then mix until stiff peaks form.
Gently fold in mascarpone cheese until smooth and fully incorporated.
Quickly dip each ladyfinger into milk or strawberry juice and arrange in a single layer in a 9x9 inch dish.
Spread half the mascarpone cream over the ladyfingers and top with half of the strawberries.
Repeat the layers with dipped ladyfingers, remaining cream, and remaining strawberries.
Cover and refrigerate for at least 4 hours or overnight for best results.
Garnish with fresh strawberry slices and mint before serving, if desired.