This recipe should make enough for four 12–13" pizzas.
Place 1/4 cup olive oil in a large pot over medium heat. Add the onion and sauté until it is limp, about 5 minutes. Add the garlic, reduce the heat to low, and cook for 7 minutes, until the edges are golden. Add the wine and bring to a simmer. Add the clams, cover the pot, and cook until the clams start to open, about 10 minutes. As they open, transfer them to a large bowl. When all the clams are cooked, simmer the liquid in the pot until it reduces to a thick glaze, about 10 minutes. Add the cream, bring to a simmer, and reduce by a quarter, 10 to 15 minutes longer. Strain through a fine-mesh sieve into a bowl and set aside. It thickens as it cools.
Meanwhile, when the clams are cool, pluck out the meat and discard the shells.
Stretch dough ball to desired size.
Working quickly, paint the entire surface of the pizza with one-fourth of the glaze. Scatter the clams over the pizza and sprinkle with chili flakes.
Cook pizza — use the broiler to char, if desired. Remove from oven when done.
Drizzle post-oven pizza with a dash of your best-quality olive oil and scatter with a quarter of the parsley. Finish with a squeeze of lemon juice.