In a large bowl, combine the yeast and 1/4 cup sugar. Warm the milk and water together to 110°F (it should feel warm but not hot to your wrist), then pour into the yeast mixture and let sit for 5-10 minutes until foamy—this proves the yeast is alive and ready to work. Stir in the egg and melted butter until combined, then gradually mix in the bread flour until a soft, shaggy dough forms. Don't overwork it at this stage; you just want the flour incorporated.

Turn the dough onto a lightly floured surface and knead for 10 minutes until smooth and elastic—you'll feel the transformation as the gluten develops. Transfer to an oiled bowl, cover with a damp towel, and let rise at room temperature for 30 minutes until puffy and increased in size. I like to set a timer so I don't forget about it, as overproofing can affect the final texture.

While the dough rises, toss the huckleberries with 1 tsp flour to prevent them from sinking or leaking juice into the dough. In a small bowl, combine the softened butter, both sugars, cinnamon, and lemon zest to create the filling. Once the dough has risen, turn it onto a clean surface and roll into a 16x13 inch rectangle. Spread the butter mixture evenly across the dough, leaving a small border, then scatter the floured huckleberries over the top in an even layer.

Starting from a long side, roll the dough tightly into a log, pressing gently as you go to seal it without crushing the berries. Seal the seam by pinching it closed. Using a sharp knife or dental floss, cut the log into 15 equal slices—I find floss creates cleaner cuts without compressing the dough. Preheat your oven to 350°F and lightly grease a 9x13 inch baking dish, then arrange the rolls cut-side up in the dish in rows.

Bake at 350°F for 35-40 minutes until the rolls are golden brown on top and spring back lightly when touched. The bottoms should be set and no longer doughy. Remove from the oven and let cool for 5 minutes—this brief rest allows them to firm up slightly so they hold together when frosted.

While the rolls are baking, beat the softened cream cheese until smooth, then gradually mix in the sifted powdered sugar, milk, and vanilla extract until you reach a spreadable consistency. Once the rolls have cooled for 5 minutes, spread or drizzle the frosting over the warm rolls so it melts slightly into the crevices. Serve warm or at room temperature.