Preheat the broiler on your oven.
Slice the baguette into ½-inch thick slices on a slight diagonal.
Thinly slice the Brie cheese and the pear.
In a small bowl, combine the crushed garlic with 2 tablespoons of olive oil.
Lightly brush each side of the baguette slices with the garlic-infused olive oil and place them on a baking sheet.
Broil the baguette slices for about 2 minutes, or until they start to turn golden brown. Flip the slices and broil the other side for another 2 minutes.
Remove the toasted baguettes from the oven and top each one with a slice of Brie. Return the baking sheet to the oven and broil for about 2 minutes, just until the Brie begins to melt.
Remove the bread from the oven and top each slice with 2 pear slices and a sprinkle of rosemary and thyme.
Return the crostini to the oven for a final time, just until the herbs become fragrant, about 1 minute.
Remove from the oven, arrange the crostini on a serving platter, and drizzle with balsamic reduction. Finish with an extra sprinkle of herbs if desired.