In a saucepan, combine the blackberries, balsamic vinegar, sugar, lemon juice, and a pinch of kosher salt. Bring to a boil over medium-high heat, then reduce the heat and let the berries simmer.

Break down the berries by crushing with a wooden spoon or potato masher. Simmer for 7 to 10 minutes until it reduces into a thick jam. It will thicken more as it cools. Transfer the jam to a small bowl and set aside to cool.

Slice the brie cheese into ½ inch thick slices.

Heat a skillet on medium heat, ensuring it doesn’t get too hot.

Spread butter on one side of four slices of bread. Place butter side down in the pan and top with brie slices.

Fry until the brie begins to soften and the bread is golden brown. Sprinkle the cheese with chopped thyme.

Spread a thick layer of blackberry jam on the remaining bread slices and place jam side down over the brie cheese.

Butter the top side of the sandwich and carefully flip. Continue frying until the bottom is golden brown and the brie is melted.

Transfer the grilled sandwiches to a cutting board. Let cool for a couple of minutes before cutting in half.