Activate the yeast. Warm your whole milk to 100 to 110 degrees F, sprinkle in the active dry yeast, and let it sit for 5 to 10 minutes until it is foamy and bubbly.
Start the dough. In a stand mixer or using your hands, rub the lemon zest into the granulated sugar until the mixture turns pale yellow. This releases all those gorgeous citrus oils. Add in the yeast mixture, egg, and vanilla, and mix until combined.
Add the dry ingredients. Fold in the bread flour and salt, then knead for 5 to 8 minutes until you have a cohesive dough.
Work in the butter. Add your cubed room temperature butter and knead for 5 more minutes, until the dough is smooth, soft, and a little glossy.
Let it rise. Cover the dough and let it rise for 1 hour, or until roughly doubled in size.
Make the compote. While the dough rises, combine all the berries and the honey in a saucepan over low to medium heat. Let it simmer for about 15 minutes, using your spatula to squish the berries down until it is nice and smooth. Set aside to cool.
Make the cream cheese filling. Beat the cream cheese until smooth, then add the heavy cream and vanilla. Slowly add the powdered sugar and beat until creamy and pipeable. Transfer to a piping bag, or set aside to spoon on later.
Make the crumble. Melt the butter and mix it with the flour, brown sugar, and lemon zest until it forms a wet sand consistency.
Shape the buns. Once your dough has risen, divide it into 6 equal balls. Press a well into the center of each, using a measuring cup for a perfect round indent or just your hands.
Fill and top. Brush the outer edges with egg wash. Pipe the cream cheese filling into each center, add about 1 tablespoon of the berry compote, then pile on your fresh blueberries, raspberries, and blackberries. Sprinkle the lemon crumble around the edges.
Bake. Bake at 375 degrees F for 18 to 22 minutes, until slightly golden on the edges.
Finish. Let the buns cool, dust generously with powdered sugar, and enjoy every single bite.