Preheat your oven to 350°F (175°C) to ensure even baking.
In a large mixing bowl, whisk together the all-purpose flour, baking soda, salt, and cream of tartar.
In another bowl, beat together the softened unsalted butter and granulated sugar until light and fluffy (about 2-3 minutes).
Add the large egg, egg yolk, and vanilla extract to the butter and sugar mixture, mixing until well combined.
Gradually add the dry ingredients to the wet mixture, mixing until just combined to avoid tough cookies.
Using a cookie scoop or tablespoon, portion out the dough onto ungreased baking sheets, leaving space between each cookie. Bake for 10-12 minutes until the edges are lightly golden. Let cool on a wire rack.
While the cookies cool, prepare the frosting by beating together the softened cream cheese, salted butter, powdered sugar, and vanilla extract until smooth and creamy.
Once cooled, spread a generous layer of cream cheese frosting on each cookie and top with an array of fresh fruits.
