Preheat the oven to 400 degrees F.
Line a baking sheet with parchment paper. Place the bacon on the baking sheet. Bake for 10 minutes, then flip and bake for 10 to 15 minutes more, until crispy and golden.
While the bacon is cooking, make the chicken burgers. Season the ground chicken all over with ranch seasoning. If your ranch seasoning does not have salt, you can also add some salt and pepper here if you’d like. But your seasoning probably already has salt! Divide the chicken into 8 equal pieces and form each piece into a ball.
Heat the oil in a cast iron skillet over medium-high heat. Once hot, press each ball of chicken burger into the skillet. Use the back of a glass/jar sprayed with non-stick spray and press the burger into the hot skillet until it’s as thin as possible. Repeat with 2 or 3 remaining burger balls, pressing them into the skillet.
After 2 to 3 minutes, gently flip the burger. Press the other side into the skillet with a clean glass. Cook for 2 minutes.
Add a slice of cheddar on top of each burger. Cook until the cheddar melts, another 1 to 2 minutes. Remove the burgers and repeat with remaining chicken.
To assemble the burgers, add some of the shredded lettuce to the bottom of one bun. Top with 2 patties (or just 1 pattie!). Top with 1 to 2 slices of bacon. Drizzle with ranch and finish with the top brioche. Serve!