Preheat your oven to 375°F (190°C). In a mixing bowl, combine powdered sugar, egg yolk, and melted butter, whisking until smooth. Gradually add vanilla extract and all-purpose flour, mixing just until combined. Press the dough evenly into a tart pan, prick the surface with a fork, and then freeze it for 1 hour to help set the shape.

After freezing, remove your crust from the freezer and line it with foil, pressing down to ensure an even bake. Bake for 15 minutes, then carefully remove the foil. Prick the bottom again and return to the oven for another 13-15 minutes or until the crust is golden brown. Let it cool completely before adding the filling.

Sprinkle the gelatin over the fresh lemon juice in a small bowl and set aside. In a large mixing bowl, beat the cream cheese until fluffy, then gradually mix in the fresh lemon zest and sweetened condensed milk. Finally, gently stir in the gelatin mixture until fully combined, ensuring no lumps remain. Pour this luscious filling into the cooled crust and refrigerate for at least 2 hours to set.

While the cheesecake chills, prepare the glazed berries. Microwave the orange marmalade until warm, then strain it to remove any solids. In a bowl, gently combine the fresh blueberries and blackberries with the warm marmalade, making sure the berries are well-coated. Set aside to cool slightly.

Once the cheesecake has set, spoon the glazed berries over the top, allowing their vibrant color to shine. For an extra touch of freshness, garnish with optional fresh mint leaves. Slice the Lemon Cheesecake with Glazed Berries into servings and enjoy the delightful blend of flavors chilled.