Preheat your oven to 200°C (180°C fan) and line a large baking tray with baking parchment. While the oven heats, lightly dust your work surface with the plain flour. Unroll the puff pastry sheet and cut it into six equal rectangles. You'll feel the pastry cool and slightly firm against your fingers; if it feels sticky, dust with a little more flour.

In a medium mixing bowl, beat the softened cream cheese with a wooden spoon until it turns smooth and creamy, with no visible lumps — this should take about a minute. Add the caster sugar, egg yolk, and vanilla extract, then stir until the mixture is pale yellow, glossy, and smells sweetly of vanilla.

Spoon roughly one heaped tablespoon of the cream cheese mixture into the centre of each pastry rectangle. Use the back of the spoon to spread it gently into a small oval, leaving a 1cm border around the edges. The filling should look thick and slightly domed.

Press 4 to 5 raspberries into the cream cheese on each Danish, pushing them down just slightly so they sit nestled in the filling. If using frozen raspberries, you'll notice they release a little juice immediately — that's fine, it adds flavour.

Fold the two shorter edges of each pastry rectangle over the filling, pinching them together gently at the centre. This creates a little boat shape. Brush the exposed pastry edges with the milk using a pastry brush; you'll see the milk sit shiny and wet on the dough.

Bake for 16 to 18 minutes, rotating the tray halfway through. The danishes are ready when the pastry is puffed, golden brown, and crisp to the touch. The raspberries will have softened and released a deep red juice that pools slightly around the filling. The kitchen will smell like a bakery.

Remove the tray from the oven and let the danishes rest on the tray for 5 minutes. This rest is crucial — the filling sets as it cools, so you won't end up with a runny mess. After resting, transfer to a wire rack. Dust with icing sugar through a fine sieve if desired, then serve warm.