Make the dough: In a large bowl, beat cream cheese and butter until smooth. Add salt (and vanilla, if using). Mix in flour just until a soft dough forms (don’t overmix).

Chill: Flatten dough into a disc, wrap, and chill at least 1 hour (or until firm).

Prep: Heat oven to 350°F (175°C). Line baking sheets with parchment.

Roll + cut: Roll dough on a lightly floured surface to 1/4 inch thick (easiest) or 1/8 inch (more delicate). Cut into 2 to 2½-inch squares.

Fill: Place about 1/2 teaspoon filling in the center of each square.

Fold + seal: Fold two opposite corners over filling so they overlap slightly. Pinch firmly at the overlap (use a tiny dab of water if needed).

Bake: Bake 12–15 minutes, until bottoms are lightly golden and tops look set.

Cool + dust: Cool 10 minutes, then dust with powdered sugar. Dust again right before serving for the prettiest “snowy” look.