Blend the red peppers, water, and broth base until smooth.
Heat a large skillet over medium heat. Add the butter and shallots; sauté until the shallots are lightly golden brown and caramelized, about 10-15 minutes.
During this time, cook the pasta according to package directions, to al dente so the noodles can finish in the sauce.
Turn the heat down to avoid splatters; add the red pepper puree and let it sizzle out for a moment. Then add the cream. Stir to combine; let it gently bubble for a few moments until it has thickened into a nice creamy sauce.
Add pasta into the sauce; let it simmer for a few moments to thicken and coat the noodles. If needed, add reserved pasta water to reach desired consistency.
Serve immediately, topped with Parmesan, basil, and/or red pepper flakes. It’s so gooood.