1. **Prepare the Cream Cheese Filling:**
1. In a small bowl, mix the softened cream cheese, granulated sugar, and vanilla extract until smooth and well combined. Set aside.

2. **Prepare the Cherry Filling (if using homemade):**
1. In a small saucepan, combine 1 cup of fresh or frozen cherries, 1/2 cup of granulated sugar, and 1 tablespoon of lemon juice.
2. Cook over medium heat until the cherries release their juices and the mixture starts to bubble.
3. In a small bowl, mix 1 tablespoon of cornstarch with 2 tablespoons of water to create a slurry.
4. Stir the cornstarch slurry into the cherry mixture and cook until thickened. Allow to cool before using.

 3. **Prepare the Puff Pastry:**
1. Preheat your oven to 375°F (190°C) and line a baking sheet with parchment paper.
2. Unfold the thawed puff pastry sheet on a lightly floured surface.
3. Cut the pastry into 9 squares (or 12 smaller squares, depending on your desired size).

 4. **Assemble the Danishes:**
1. Place a small spoonful of cream cheese filling in the center of each pastry square.
2. Top the cream cheese with a small spoonful of cherry filling.
3. Fold the corners of each square towards the center to form a little packet or triangle, pinching the edges to seal.

5. **Apply Egg Wash:**
1. Brush the tops of each danish with the beaten egg for a golden finish.

6. **Bake:**
1. Bake in the preheated oven for 15-20 minutes, or until the pastries are puffed and golden brown.

 7. **Cool and Serve:**
1. Allow the mini danishes to cool slightly on a wire rack before serving.