In a medium bowl, combine taco seasoning and beef. Mix gently just until combined.
Form mixture into 8 (1/4" thick) patties. Set aside one cup of cheese for topping. Scoop 2 ounces of the remaining cheese in the center of one patty place a second patty on top. Press the two together and crimp the edges with your fingertips sealing it so the cheese does not leak out. Repeat until all burgers are prepared.
Make a slight indentation in the center of the burgers to prevent it from doming up in the center. The indentation will rise as your burger cooks.
Grill until golden brown and slightly charred (about 5 minutes), turning once (cook for 4 minutes on the other side for medium). Avoid pressing with a spatula, you don't want the juice or cheese to escape!
Carefully add 1 tablespoon of cheese to the top of each burger for the last minute of cooking. Set burger aside and allow to rest for 5 minutes before cutting.
Place buns on grill (inside down) for about 1 minute, until they are golden. Remove buns and place 1 tablespoon remaining cheese on top of each bottom bun, then add burger, ΒΌ cup salsa and top bun.