Heat oven to 350 degrees. Line a sheet pan with parchment paper. With a pastry brush, lightly brush the slices of baguette with olive oil. Place pieces on pan, season with salt and pepper. Bake in oven for about 5-7 minutes until golden.
Blanch trimmed asparagus in rapidly boiling salted water for about 3 minutes. Transfer immediately to an ice bath. Remove once cooled to dry, then cut into 1-inch pieces.
To assemble: Place a small piece of salmon on top of the crostini, then two pieces of asparagus, and top with one small slice of brie. Garnish with freshly cracked pepper.