Preheat the oven to 400F / 200C and prepare a 9x9 baking dish with cooking spray.
Bring a large pot of water to a boil, then add a big pinch of salt and the pasta. Cook according to the package directions, adding the broccoli to the pot 2-3 minutes before the pasta is al dente. Cook together; the broccoli should be bright green. Drain the pasta and broccoli and set aside.
Melt the butter in a medium saucepan over medium-low heat. Add the flour and stir for 2-3 minutes, until combined. Add the milk, turn up the heat slightly, and whisk until no clumps remain and the mixture thickens. Add the cheese and stir until melted. Add the chipotle powder, salt, and pepper. Taste and adjust seasonings to your liking.
Remove from the heat, then add the cooked pasta and broccoli to the cheese sauce. Stir until well combined.
Pour the mac and cheese into the prepared baking dish and top with breadcrumbs. Bake for 15 minutes, uncovered, until the top is golden brown. Or feel free to skip this step and eat it right out of the pot, but we like the baked version's texture the best.
If prepping this, allow it to cool slightly out of the oven. Then divide among meal prep containers. Allow to cool completely before storing in the refrigerator or freezer.