- Bring a large pot of salted water to a boil. Add the Angel Hair pasta to the boiling water and cook according to the package instructions until just barely al dente. (2 mins) Drain the pasta reserving some for the sauce; set aside.
- Meanwhile, melt 2 tablespoons of the vegan butter in a large, high-sided skillet over medium heat until foaming. Add the panko and cook, stirring occasionally, until lightly browned, 5 minutes. Transfer to a bowl.
- Wipe out the skillet with a paper towel. Melt the remaining 2 tablespoons butter in the same skillet over low heat, stirring so it melts evenly. Melt the butter and add the lemon slices (seeds removed), cook for 5 minutes, stirring often, until the butter is browned, small brown bits are visible and you have a nutty aroma. Now add the garlic and rosemary and cook for an additional 2 mins until garlic is golden. Season with salt and pepper. Remove the skillet from the heat.
- Add 2 tbsp of cooked pasta water to the sauce, stir, now and the cooked pasta to the skillet and use tongs to toss together until the pasta is evenly coated with the brown butter.
- Top with toasted Panko, additional lemon juice, and lemon zest.