Trim any visible fat from the top sirloin steak. Slice the beef into thin strips, about 1/8 to 1/4-inch thickness, cutting against the grain.
In a zip-top bag or medium food storage container, mix together the soy sauce, brown sugar, vinegar, liquid smoke, pepper, salt, garlic powder, and onion powder for the marinade. Place the beef in the marinade and toss or stir to coat it evenly. Place the container in the refrigerator and let the meat marinate for at least 3 hours, or overnight.
Once the beef has fully marinated, preheat the oven to 300°F. Prepare two baking sheets with an oven-safe rack in each. Adjust oven racks so that both are as close as possible to the middle of the oven
Remove the meat from the fridge. Lay the strips of beef on the racks. Wrap one piece of beef tightly around the probe of an oven-safe meat thermometer.
Place both baking sheets in the oven one on the upper-middle rack, the other on the lower-middle rack. Bake until the thermometer inside the meat reaches 160°F, about 15 minutes.
When the meat hits that temp, crack open the oven door for 1 minute to let some heat escape, and reduce the oven temperature to 170°F. Close the oven door.
Continue dehydrating the meat in the oven for about 2 to 4 hours, or until it reaches the proper texture—pliable without any moisture seeping out. Total time will depend on the thickness of the meat and your oven. Start checking for doneness around 2 hours.
When the jerky is done, remove it from the oven, let cool, and enjoy.