Place golden raisins in a small bowl and cover with water. Set aside to plump.
As you prepare topping, bring a large pot of salted water to a boil and cook spaghetti until al dente according to the package directions.
In a large cast iron or skillet, heat 2 tablespoons of olive oil over medium heat. Once hot, add garlic and cook for 1 minute.
Bring heat down to low and add another tablespoon of olive oil and the breadcrumbs. Toast for 2-3 minutes until golden in color.
Add walnuts to skillet and toast for another 2 minutes.
Mix in drained raisins, parsley, and capers and continue cooking for another 2 minutes. Remove from heat and set aside.
Once cooked, drain the spaghetti, reserving about ½ cup of the pasta water. Stir pasta water into the topping.
Alternate layers of spaghetti and topping in a large pan or serving dish. Drizzle remaining 4 tablespoon olive oil over top.
Top with red pepper flakes and additional parsley if desired. Serve hot.
