Cook the pasta according to package directions. Reserve 1/2 cup of the cooking liquid, drain the pasta, and return it to the pot.
Meanwhile, in a microwave-safe bowl, combine the broccoli, garlic, and 1/2 cup water. Cover and cook on high, stirring once halfway through, until the broccoli is tender, 5 to 6 minutes.
Transfer the mixture (liquid included) to a food processor. Add the basil, oil, zest, and 3/4 tsp salt, and purée until smooth to make pesto.
Toss the pasta with the pesto and 1/4 cup of the reserved liquid (adding more liquid if the pasta seems dry). Sprinkle with almonds and Parmesan, if desired.