How to Make It
Preheat oven to 350°F. Stir together berries, brown sugar, and lemon zest and juice in a large bowl. Transfer berry mixture to a rimmed baking sheet; spread in an even layer. Bake in preheated oven until berries are tender but still hold their shape, 25 to 30 minutes. Use a spatula to scrape fruit and pan juices into a heatproof bowl. Keep warm if serving immediately, or let cool completelym and store, covered, in refrigerator up to 1 week.
Preheat oven to 200°F. Melt 6 tablespoons butter in a small stainless steel skillet over medium. Cook, stirring often, until butter solids are golden brown and have a toasty aroma, 3 to 5 minutes. Immediately transfer brown butter to a medium heatproof bowl. Whisk in milk and sour cream until combined. Add eggs and vanilla; whisk until combined.
In a separate large bowl, whisk together flour, sugar, baking powder, and baking soda. Add brown-butter mixture to flour mixture; gently stir just until there is no powdery flour visible (batter should be lumpy).
Heat a large cast-iron griddle or large skillet over medium, or heat an electric griddle to 375°F. Test the griddle with a few drops of water; if they sizzle on contact, it’s ready to cook the pancakes. (If the griddle is smoking, it is too hot.) Grease griddle with 1 tablespoon butter. Using a ladle, add up to 4 scoops of batter (about 1/2 cup per pancake) to griddle, using up about half of the batter. Working quickly, use the bottom of the ladle to spread the batter into even circles. Cook until bottoms of pancakes are deep golden brown and tops have bubbles all over, 2 to 3 minutes, adjusting heat as necessary. Flip pancakes; cook until done, 1 to 2 minutes. Transfer pancakes to a serving platter, and place them, uncovered, in preheated oven while you cook second batch. Repeat process with remaining batter and remaining 1 tablespoon butter. Serve pancakes with the warm berry syrup and, if desired, additional butter.