Make the tart shells first. Cube the butter beforehand and place into the freezer until icy cold. Place flour, salt and sugar in a food processor and pulse to combine.
Add cold butter to the food processor and pulse into fine crumbs. Add the cold heavy cream 1 tablespoon at a time, pulsing after each addition, until the dough starts to come together but stays slightly crumbly.
Bring the dough together into a ball, wrap in plastic wrap and refrigerate for one hour.
Preheat oven to 375°F. Roll out dough into a thin sheet on a lightly floured work surface. Using a round cookie cutter, cut out circles.
Gently press each disk of dough into a mini cupcake tin to shape the shell. Pierce the bottoms with a fork to prevent bubbling, and bake in preheated oven until golden brown. Allow the shells to cool slightly in the pan before removing to a wire rack to cool.
Add a spoonful of lemon curd into the center of each tartlet. Transfer cheesecake filling to a pastry bag and pipe a dollop on top of each tartlet. Top with a variety of fruits to make a rainbow of tartlets.
Keep tartlets refrigerated until ready to enjoy.
In a medium bowl, whisk together the lemon juice, eggs, egg yolks, sugar and vanilla. Strain the mixture through a fine-mesh strainer to remove impurities.
Cook the mixture over medium heat, stirring constantly, until it thickens into a custard, about 7 minutes.
Add the butter to the hot custard; whisk until butter is completely melted. Cover the lemon curd with plastic wrap so it touches the surface; cool in refrigerator.
Next, prepare the cheesecake filling. Pour cold heavy cream into a mixer bowl and add the sugar and vanilla extract. Whisk on medium speed to soft peaks.
Add the whipped cream cheese, and whisk again until mixture is smooth. Keep cheesecake filling refrigerated until ready to use.