Preheat the oven to 350°F (175°C).
In a mixing bowl, combine flour and sugar. Cut in the butter until crumbly.
Add the egg yolk and mix until the dough comes together.
Press the dough evenly into the bottom and sides of a tart pan.
Bake the crust for 15-20 minutes or until lightly golden brown.
While the crust cools, prepare the filling by beating the cream cheese until smooth.
Add powdered sugar, vanilla extract, and sour cream; mix until well combined and smooth.
Pour the filling into the cooled crust and smooth the top with a spatula.
Bake for 25-30 minutes until the edges are set but the center is slightly jiggly.
Allow the tart to cool, then top with sliced strawberries sprinkled with sugar.
Refrigerate for at least 2 hours before serving for the best texture and flavor.
