In a medium bowl, combine graham cracker crumbs, melted butter, and sugar until the mixture is moist and holds together when pressed. Firmly press this mixture into the bottom and up the sides of a tart pan to create a solid crust. Chill the crust in the refrigerator for at least one hour.

Using a stand mixer, beat the heavy whipping cream with vanilla extract on medium-high speed until stiff peaks form, about 3-5 minutes. In a separate bowl, blend softened cream cheese, powdered sugar, lemon zest, and juice until smooth and creamy. Gently fold the whipped cream into the lemon-infused mixture.

Once the graham cracker crust has fully chilled, spread the creamy lemon filling evenly over the crust. Carefully arrange fresh strawberries, blueberries, and raspberries on top, creating a beautiful and colorful display.

After assembling your Summertime Berry Tart, cover it with plastic wrap and refrigerate for an additional hour.