In a medium bowl, combine graham cracker crumbs, granulated sugar, and melted butter. Mix until well combined.

Press the mixture firmly into the bottom and up the sides of a muffin tin to form tartlet shells. Chill in the refrigerator for at least 30 minutes to set.

In a large bowl, beat the softened cream cheese, powdered sugar, and vanilla extract until smooth and creamy.

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

Remove the tartlet shells from the refrigerator and fill each shell with the cream cheese mixture, smoothing the top with a spatula.

Arrange the sliced strawberries, blueberries, and raspberries on top of the cream cheese filling in a decorative pattern.

Refrigerate the tartlets for at least 1 hour before serving to allow the flavors to meld.

Garnish with fresh mint leaves if desired before serving.