In a small saucepan, warm the milk over low heat until it's lukewarm (about 110°F). In the bowl of a stand mixer fitted with a dough hook, combine the bread flour, instant yeast, and salt. Add the egg yolk. Stir the honey and olive oil into the warm milk, then pour the mixture into the flour. Mix on low speed until a rough, shaggy dough forms. Increase the speed to medium and knead for about 7 minutes, until the dough is smooth, elastic, and slightly sticky. (Alternatively, mix by hand in a large bowl, then turn out onto a lightly floured surface and knead for 10-12 minutes.) Transfer the dough to a lightly oiled bowl, cover with plastic wrap, and let it rise in a warm spot for 1 to 1 1/2 hours, until doubled in size.

Turn the risen dough out onto a lightly floured surface and divide it into 10 equal pieces. Roll each piece into a smooth ball, pinching the seam on the bottom to create a neat dome. Place the dough balls on two parchment-lined baking sheets, leaving plenty of space between them. Cover with a damp kitchen towel and let them proof for 30 minutes. About 10 minutes before baking, preheat the oven to 350°F. Bake the buns for 18-20 minutes, until deep golden brown and puffed, rotating the trays halfway through for even baking. Transfer to a wire rack to cool completely.

While the buns cool, puree 200 grams (about 7 ounces or 1 1/3 cups) of the raspberries in a food processor. Press the puree through a fine-mesh sieve to remove the seeds. In a large bowl, whip the heavy cream, confectioners' sugar, and raspberry puree together until light and mousse-like. Gently crush the remaining 100 grams (about 3 1/2 ounces or 2/3 cup) raspberries and fold them into the whipped cream. Cover and refrigerate until ready to use.

Once the buns are completely cool, split each one horizontally through the middle, leaving one side attached like a book. Pipe or spoon the raspberry cream into the center, then smooth the top and sides with a small spatula. Dust generously with extra confectioners' sugar before serving.