Spaghetti Puttanesca

Name: Spaghetti Puttanesca
Ingredients: 6-8 anchovy fillets, mashed to a paste; 3 tablespoons unsalted butter, softened; 2 tablespoons olive oil; 1 teaspoon red pepper flakes, or to taste; 1/2 teaspoon dried oregano (Turkish/Mediterranean variety); 1/4 cup capers in brine or vinegar (not rinsed), plus a little of the brine; 4-8 garlic cloves, minced (how much is a matter of taste); 1 28-oz can crushed tomatoes (preferably San Marzano); 1/4 cup kalamata olives, pitted and sliced; 1 pound dried spaghetti; 2 tablespoons basil chiffonade (optional); salt and pepper, to taste