For the beans: Add the dry beans to a large bowl with double their volume in water. Allow the beans to soak overnight in the refrigerator.
Slice the sausage into ½-inch diagonal pieces. Add cooking oil and sliced sausage to a large pot over medium heat until the sausage pieces are browned. While the sausage is cooking, dice the “trinity” (onion, bell pepper, and celery) and mince the garlic cloves. Remove the cooked sausage with a slotted spoon to a clean bowl. After removing the cooked sausage, add the “trinity” and garlic to the pot. Do not drain the fat left from the cooked sausage. Sauté the vegetables over medium heat until translucent.
Add the smoked paprika, garlic powder, onion powder, Season-All, and bay leaves to the pot. Drain and rinse the beans. Add them to the pot along with 6 cups of water and stir to combine the ingredients.
Place a lid on the pot, turn the heat up to medium-high, and bring it to a boil. Once boiling, reduce the heat to medium-low and let it boil for 30 minutes, stirring occasionally and replacing the lid each time you stir.
After boiling for 30 minutes, add your cooked sausage to the pot and continue cooking for 30 additional minutes or until the beans are tender.
Begin to smash the beans with the back of a spoon against the side of the pot.
Add the butter and continue smashing the beans while letting the pot simmer without a lid for 25 minutes. You can add the cayenne pepper at this stage if you desire.
For the rice: While the beans are simmering for the final 25 minutes, cook the rice. Add the rice and 3 cups water to a sauce pot. Add salt and stir. Place a lid on top, turn the heat on high, and bring to a boil. Once boiling, turn the heat down to medium-low and let the rice simmer for 15 minutes until soft. Turn the heat off and pour the rice into a colander and rinse with water over the sink. Place the colander in the pot to allow the excess water to drain and cover with a lid until you are ready to plate the meal.
Once the red beans have thickened, add the chopped parsley. Stir to combine. Taste the red beans and add ½ tablespoon of salt if needed. Serve the red beans in a bowl topped with a scoop of rice and garnish with sliced green onions on top.