01 - Preheat your oven to 400°F. Line a large baking sheet with parchment paper and set aside.
02 - Lightly flour your work surface and unfold the thawed puff pastry sheet. Using a 3-inch heart-shaped cookie cutter, cut out 16 heart shapes. Place 8 solid hearts on the prepared baking sheet, spacing them 2 inches apart.
03 - Take the remaining 8 hearts and use a 2-inch heart cutter to remove the centers, creating heart-shaped frames. Reserve the small cutout hearts for baking separately as bonus treats.
04 - Brush the edges of the solid hearts on the baking sheet with the beaten egg. Carefully place the heart frames on top, aligning edges and pressing gently to seal.
05 - In a small mixing bowl, combine the softened cream cheese, granulated sugar, and vanilla extract. Beat with a fork or electric mixer until completely smooth and creamy.
06 - Spoon approximately 1 tablespoon of cream cheese filling into the center of each heart cavity. Top with 1/2 tablespoon strawberry preserves and arrange 2-3 thin strawberry slices on top.
07 - Lightly brush the exposed pastry edges with remaining egg wash. Bake for 16-18 minutes until deeply golden and puffed. The pastry should feel crisp and the filling bubbly.
08 - Let the danishes cool on the baking sheet for 10 minutes while you prepare the glaze. Whisk powdered sugar, 1 tablespoon milk, and vanilla until smooth. Add remaining milk if needed to reach drizzling consistency.
09 - Drizzle the vanilla glaze over the cooled danishes in a decorative pattern. Serve warm or at room temperature. Best enjoyed within 4 hours of baking.