Bring a large pot of well salted water to a boil. Add the penne and cook it according to the package directions. Before draining the pasta, scoop out 1-2 cups of pasta water.
Slice the chicken breast down through the meat into 1/4 inch thick cross sliced pieces and then cut the pieces into bite-sized chunks. Similarly, slice up the chorizo into 1/4 inch thick bite-sized pieces.
In a large, deep skillet, heat the oil on medium-high heat until shimmery. Season the chicken well with salt and pepper and lay the pieces in the skillet. Sear them, unmoving for 1-2 minutes. When they are ready they will loosen from the bottom of the pan. Flip them over and sear until the chicken is cooked through, another 1-2 minutes. Transfer the chicken to a bowl.
Add the chorizo to the now empty skillet and give it a good sear on both sides, 3-4 minutes total. Remove the chorizo to the bowl.
Lower the heat to medium-low and add the vodka. Cook for about 30 seconds. The vodka will be almost cooked off. Then add the marinara sauce, red pepper flakes (if using), and cream and bring the sauce to a simmer.
Once the pasta is done, add it to the skillet along with 1 cup of the pasta water. Simmer the pasta with the sauce for about 2 minutes, adding more pasta water if needed. Add the meat back in to warm it up. Sprinkle the basil over the top and serve.