Fill a large pot with water and bring to a boil. Salt the water to your taste and add the spaghetti to the pot. Cook according to packaging instructions and drain.
In a large pan over medium heat, add oil and salami pieces. Cook until the salami pieces are crispy.
Add the onion, bell pepper, garlic, sofrito, and corn. Cook until the vegetables are softened, then add tomato sauce, capers, vinegar, adobo, sazón, and oregano and mix well.
Add ¼ cup evaporated milk to the pan and mix until the sauce is combined. Add the remaining ¼ cup evaporated milk if you prefer the pasta creamier.
Lower the heat and add the spaghetti and butter to the pan. Mix well until fully combined, and serve with tostones and pan de agua. Buen provecho!