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 turn down the heat and allow the berries to simmer. Break down the berries by crushing with a wooden spoon or potato masher.

Simmer the blackberries for 7 to 10 minutes until it reduces into a thick jam. 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.

Spread butter on one side of four of the bread slices. Place butter side down in the pan. Top the bread with the brie slices. Let the bread slowly fry until the brie begins to soften and the bread is golden brown. Sprinkle the cheese with the 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 bread and then carefully flip.

Continue to fry the sandwich until the bottom piece of bread 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 with a sharp knife.