Preheat the oven to 190C (370F) and line two baking sheets with parchment paper. If you use puff pastry, follow the baking temperature and time mentioned on the package.
In a bowl, add the cream cheese, sugar, lemon zest, and vanilla extract. Whisk to combine. Place the filling into a piping bag and cut off the end. Or you can spoon the filling right on top of your pastry squares.
Cut your Danish pastry (if you use store-bought puff pastry, thaw it until softened first) into twelve 3” by 3” (8cm by 8cm) squares. Prick the center, where the filling will be, with the fork several times. Spread around 1 tablespoon of the filling in the center of each square.
Arrange strawberry cubes on top. I used 3-4 slices per portion.
If you use my Danish pastry, cover arranged squares with plastic wrap and let them proof for 20-40 minutes at room temperature or until puffy before baking. If you use puff pastry, bake right away. Whisk the egg yolk and milk in a bowl and brush on exposed pastry corners. Bake one sheet at a time for 16-18 minutes or until deep golden and puffed up.