In a medium bowl, combine graham cracker crumbs, melted butter, and granulated sugar. Mix until well combined and the mixture resembles wet sand.

Press the graham cracker mixture firmly into the bottom and up the sides of a 9-inch tart pan. Use the back of a measuring cup to ensure an even layer. Refrigerate for 30 minutes to set.

In a large mixing bowl, beat the softened cream cheese with an electric mixer until smooth. Gradually add powdered sugar and vanilla extract, mixing until well combined.

In a separate bowl, whip the heavy cream until stiff peaks form. Gently fold the whipped cream into the cream cheese mixture until fully incorporated.

Add lemon juice and lemon zest to the mixture, folding gently until combined.

Pour the lemon filling into the chilled graham cracker crust, spreading it evenly.

Top the tart with mixed fresh berries, arranging them as desired.

Refrigerate the tart for at least 2 hours before serving to allow it to set properly.