In Level 7: One Bullet, when you get the "Find a way into the Weyland-Yutani Facility to save 
Bella" objective, follow the stairs to a door, and exit the interior to enter a rocky exterior
area with lava flowing down a cliff to your right. Run partway up the path ahead, and look to 
the right across the chasm with a scoped weapon to find a box of donuts. Shoot them, and they
will disappear. Then, look to where your teammates are waiting to see a giant donut appear 
uphill. It will roll down, launch off the cliff, and explode in the lava.