01 - Preheat oven to 400°F. Line a large baking sheet with parchment paper.
02 - On a lightly floured work surface, unfold the thawed puff pastry sheet. Using a 3-inch heart-shaped cookie cutter, cut out 16 heart shapes. Transfer 8 solid hearts to the prepared baking sheet.
03 - Using the remaining 8 heart cutouts, press a 2-inch heart-shaped cutter into the center of each to remove the middle portion, creating decorative heart frames. Set aside.
04 - Lightly brush the edges of the 8 whole hearts on the baking sheet with beaten egg. Carefully place the heart frames on top, pressing gently to seal the layers together.
05 - In a small mixing bowl, combine softened cream cheese, granulated sugar, and vanilla extract. Beat with a fork or handheld mixer until completely smooth and creamy.
06 - Spoon approximately 1 tablespoon of cream cheese mixture into the center well of each pastry. Top with 1/2 tablespoon strawberry preserves, then arrange 2-3 thin strawberry slices over the preserves.
07 - Brush the exposed pastry edges with remaining beaten egg for a golden, glossy finish.
08 - Bake for 16-18 minutes until pastries are deeply golden, puffed, and cooked through. Allow to cool on the baking sheet for 10 minutes to set the filling.
09 - While pastries cool, whisk powdered sugar, 1 tablespoon milk, and vanilla extract in a small bowl until smooth. Add additional milk 1/2 teaspoon at a time to reach drizzling consistency.
10 - Drizzle glaze generously over cooled danishes. Serve immediately while slightly warm or at room temperature.