In a large pot or skillet over medium, add the oil, garlic, shallots and Calabrian chili paste; cook for 2 minutes, stirring constantly.
Add the beans, pasta, and broth, plus about 1 cup water to cover the pasta (you can add more water or broth as is cooks if it’s looking dry.)
Bring to a boil over high heat, stirring frequently, then reduce to medium-low to simmer until the pasta is almost cooked through, about 8 minutes.
Stir in spinach, lemon zest and juice and parmesan and season to taste with salt.
Serve with more parm and red pepper flakes, if desired.
