01 - In a small bowl, gently combine the blueberries, honey, and lemon zest. Set aside.
02 - Lightly spread softened butter on one side of each slice of bread.
03 - Place two bread slices, buttered side down, on your work surface. Arrange the brie slices evenly over the bread. Spoon the prepared blueberry mixture on top of the cheese. If using, sprinkle with fresh basil and black pepper.
04 - Top each sandwich with the remaining bread slices, ensuring the buttered side faces upwards.
05 - Heat a large skillet or griddle over medium heat. Carefully place the assembled sandwiches in the hot skillet. Cook for 3 to 4 minutes per side, pressing gently with a spatula, until the bread is golden brown and the brie is fully melted and gooey.
06 - Remove the grilled sandwiches from the skillet. Allow them to cool for 1 to 2 minutes before slicing and serving warm.