Cover and cook until clams are open, 5–7 minutes (about 4 minutes for cockles). Quickly stir in wine and simmer until only a couple of tablespoons of liquid are left in pot.
red pepper flakes and cook, stirring, until garlic is golden all over and anchovies are dissolved. Cook garlic, stirring often, until golden around the edges, about 3 minutes. Heat ¼ cup oil in Dutch oven over medium. Using a mandoline if you have one (if not, use a really sharp knife), very thinly slice remaining 9 garlic cloves. Add lemon zest, season with salt, and toss to combine set aside. Add breadcrumb mixture and cook, stirring often, until crumbs are golden and crisp, 5–7 minutes. oil in a large Dutch oven over medium-high. Add bread and pulse several times until fine crumbs form.
Meanwhile, pulse 3 garlic cloves in a food processor until chopped. Diamond Crystal salt and 10 cups water to a boil in a large pot.
