Preheat oven to 350 degrees F (175 degrees C). Slice the baguette into 24 rounds. Brush bread rounds lightly with olive oil. Place bread rounds on a baking sheet.
Toast the bread rounds in the preheated oven just until crisp, 5 to 8 minutes. Meanwhile, slice Brie cheese into 24 equal pieces. Remove toasted bread from oven; top each round with a slice of Brie cheese. Return the crostini to the oven to melt the cheese, about 5 minutes.
Preheat the oven's broiler and set the oven rack about 6 inches from the heat source. In an ovenproof casserole, stir together the oysters, butter, any remaining olive oil, salt, and pepper.
Broil in the preheated oven until the oysters begin to curl at the edges, about 5 minutes. Remove the oysters; place one oyster on top of each crostini. Top the crostini with red pepper strips; serve warm.
