In a small bowl, soak the capers in water for about 10 minutes. After soaking, squeeze out the water lightly and set the capers aside.
Slice the tomatoes in half if they are small or quarters if they are big then squeeze out the seeds. Mince them then set aside.
In a bowl or the container of the immersion blender, mix the capers, garlic, anchovies, parsley, oregano, salt, 1/8 cup of the minced tomatoes, and parsley. Blend.
Mix the blended mixture with the remaining minced tomatoes, cover and let it sit for 2 hours in a cool part of the kitchen or in the refrigerator.
Over medium-high heat, bring some water to a boil in a saucepan. When it boils, add some salt then the spaghetti. Cook according to the number of minutes indicated in the box.