Preheat oven to 375°F. Line a baking sheet with parchment paper or a silicone baking mat and set aside.
In a medium bowl, beat together the cream cheese, powdered sugar, vanilla, and strawberry jam until smooth and creamy.
Unroll the crescent roll dough and line the triangles up in a way that you create 4 rectangles. Pinch the dough together along the edge of the triangles to create the rectangles.
Divide the cream cheese mixture evenly between the four pieces of dough, spreading on one half of each rectangle and leaving a thin border around the edges. Arrange the strawberry slices on top of the cream cheese mixture.
Fold the dough over the filling so that edges meet, and press along edges firmly with a fork to seal.
Brush the top of each pastry with milk and sprinkle with sugar. Cut three diagonal slits on top of each pastry using a knife.
Bake for 13 to 16 minutes, or until the pastries are a deep golden brown. Remove from the oven, and allow to cool for around 10 minutes.