Preheat oven to 375°.
In a large skillet over medium heat, cook bacon until crispy, about 10 minutes. Drain bacon on paper towels and leave a couple tablespoons of bacon fat in the skillet.
Add asparagus to skillet and cook until asparagus is bright green and only slightly tender. Season with salt and pepper then remove from skillet and squeeze lemon juice on top.
Chop bacon and asparagus into bite-size pieces. Set aside.
Trim rind off of brie with a sharp knife and then cut brie into small square pieces, about 1-inch wide.
On a lightly floured surface, unroll crescent dough into a large rectangle. Pinch together any seems that have opened. Cut dough into 24 squares.
Spray a 24-cup mini muffin tin with cooking spray. Place a crescent square into each muffin cup then fill with brie, cooked bacon, and asparagus.
Bake until crescent is golden (not burnt), and cheese is bubbling and melting over, about 15 minutes.