Heat a skillet with a lid over medium heat. Add the bacon and cook, turning occasionally, until crisp, about 12 minutes.
Meanwhile, mix together the ground beef, salt and pepper, Worcestershire sauce and garlic in a small bowl until well combined. Divide the mixture into 6 equal mini patties. Set aside.
Remove the bacon from the skillet and set aside. Add the burger bites and cook until well browned all over and cooked through, 4 to 5 minutes per side. Add 2 of the quartered pieces of cheese to the top of each bite and cover the skillet with the lid. Allow the cheese to melt, 1 minute. Remove the bites to a plate.
Tear each bacon piece into bite-size pieces. Start building up the bites by placing a piece of bacon on top of each patty, then a couple of folded leaves of spinach, a couple of pickles, a dollop of your favorite burger condiment, and a half a tomato, securing it all with a toothpick or small skewer. Repeat with the remaining ingredients until all the bites are built, and serve.