Cut each zucchini in half widthwise, then cut each half into thin strips lengthwise (I used a mandolin for this). Place strips on a parchment-lined baking sheet in an even layer (you may need multiple baking sheets). Brush zucchini with olive oil and season lightly with kosher salt. Working in batches, broil zucchini until tender and golden in spots (about 8 minutes per batch).

Meanwhile, cook the bacon in 1 tablespoon of butter in a large skillet over medium heat until just crisp (10 - 15 minutes). Using a slotted spoon, transfer the bacon to a paper towel-lined plate.

Add another tablespoon of butter to the skillet along with the rosemary and garlic. Cook just until fragrant (about 30 seconds). Add the breadcrumbs, and toss in the fat to evenly coat. Cook, stirring frequently, until the crumbs turn golden and crunchy (about 5 minutes). Take the skillet off the heat, and stir in the parsley and lemon zest. Season to taste with salt and pepper.

To serve, toss broiled zucchini with the bacon breadcrumbs. Garnish with a few parsley leaves if you desire. Enjoy immediately (leftovers are good too though!).