Warm the milk gently until it's lukewarm, not hot, then combine it with the flour, yeast, salt and egg yolk in your mixer bowl. Stir the honey and olive oil into the warm milk before pouring it into the flour mixture. Knead on medium speed for about 7 minutes until the dough turns smooth, elastic, and slightly sticky to the touch.
Move the dough into a lightly oiled bowl, cover it, and set it somewhere warm and draft-free. I usually pop mine near a sunny window or inside a switched-off oven with the light on. Give it 1 to 1.5 hours, or until it has doubled in size and feels puffy when you press it.
Divide the dough into 10 even pieces and roll each into a tight ball, pinching the underside so the top stays smooth and domed. Space them out generously on two lined trays since they'll expand quite a bit. Cover with a damp tea towel and let them prove for another 30 minutes.
Heat your oven to 180°C fan (gas mark 6) about 10 minutes before baking. Slide the trays in and bake for 18-20 minutes, rotating them halfway so every bun browns evenly. They're done when deeply golden and sound slightly hollow when tapped. Cool completely on a wire rack.
While the buns cool, blitz 200g of raspberries in a food processor, then push the purée through a fine sieve to remove seeds. Whip the cream with icing sugar and the raspberry purée until it turns light and mousse-like. Fold in the remaining crushed raspberries for texture, then chill until you're ready to assemble.
Split each cooled bun down the centre, keeping one side attached like a hinge. Pipe or spoon in a generous amount of raspberry cream, smoothing the sides neatly with a spatula. Finish with a dusting of icing sugar right before serving for that classic bakery look.