Preheat oven to 425 degrees. Place bacon in a large, empty pan over medium-high heat. Cook to desired doneness, 3-6 minutes per side. Transfer to a paper towel-lined plate, keeping grease in pan. Once bacon is cool, chop into bite-sized pieces.

Meanwhile, peel, halve and thinly slice onion. Add onion and a pinch of sugar to pan used for bacon. Cook, tossing, until onion is a deep golden, 10-12 minutes. Stir in 1 tsp balsamic vinegar (we'll be using the rest later) and continue cooking until liquid has evaporated, about 3 minutes longer.

Halve, core, and slice apple. Heat a large drizzle of olive oil in another large pan over medium-high heat. Add apple in a single layer. Cook, tossing occasionally, until softened, 5-7 minutes.

While onion and apple cook, place flatbreads on a baking sheet. Toast in oven until very lightly toasted, 5-7 minutes. In a small bowl, combine ricotta, a drizzle of olive oil, and a pinch of salt and pepper.

Spread ricotta mixture over flatbreads. Evenly scatter onion, apple, and bacon over each. Return sheet to oven and bake until toppings are toasty and lightly crisped, 5-7 minutes.

Drizzle flatbreads with honey and remaining balsamic vinegar. Cut into slices and serve.