n a medium bowl, gently crush 1 cup of mixed berries using the back of a wooden spoon or a potato masher — just enough to release their juices without turning them into jam. Sprinkle in the sugar, fresh lemon zest, and a splash of lemon juice. Give it a stir until you see a glossy syrup forming at the bottom. Fold in the remaining 2 cups of whole berries so they’re beautifully coated. Let the mixture rest at room temperature for 1 to 2 hours to soak up all that flavor magic.
When the berries are bursting with syrupy goodness, crank your broiler to high. Move the oven rack as close to the top as you safely can. Lay thick slices of rustic bread on a baking sheet, and crown each with generous slices of Brie — let them spill slightly over the edges for that irresistible melt. Slide the tray under the broiler for about 30 seconds to 1 minute. Watch it like a hawk — you’re aiming for soft, bubbly Brie, not a kitchen fire!
Once the Brie is gooey and just starting to ooze, remove the toasts and transfer them to serving plates. Spoon a generous heap of the macerated berries (and that luscious syrup!) over the top. Serve immediately while everything is warm and melty — and yes, you’ll need extra napkins.
