Pre-heat the oven to 375°F.
Arrange a cooling rack over a parchment or foil-lined baking sheet for easy clean up.
Cut the ends off the entire head garlic to expose all of the cloves. Season the garlic with a little salt, some black pepper, and a drizzle of EVOO, then wrap in foil.
Cut the tomatoes in half and place in a bowl. Lightly dress the tomatoes by drizzling with EVOO. Season the tomatoes with salt, pepper and marjoram, and arrange on the baking sheet cut-side down. Bake the tomatoes for 20-25 minutes, then flip the tomatoes and roast for 20 minutes more. Roast the garlic for 45-50 minutes alongside the tomatoes.
Place about 2/3 of the tomatoes in a food processor. Coarsely chop the remainder of the tomatoes and reserve. Squeeze the garlic out of its skin and add to the food processor, pulsing until smooth. Add the mixture to a Dutch oven and add the olives, anchovies, capers, and chili pepper. Cook for 5 minutes to allow the flavors to meld. Transfer to a small container for a make-ahead meal and refrigerate, or transfer to a serving bowl. Store the chopped tomatoes separately, or add to the serving bowl.
To serve, bring water to a boil, salt the water and cook the pasta to al dente. Reheat the sauce. Toss the pasta with the sauce for 1 minute, to coat. Serve in shallow bowls with lots of parsley, and drizzle with more EVOO.