Tip:There are three sizes of hard-shell clams: Chowder clams are the largest, then cherrystones, followed by littlenecks. Stick with cherrystones or littlenecks for these recipes because they’re small enough to eat whole in one bite.
Position a rack in the center of the oven and heat the broiler on high.
Arrange the clams on a heavy-duty rimmed baking sheet. Broil until they open, 5 to 7 minutes, removing each clam with tongs as it opens and transferring it to a clean rimmed baking sheet to cool. Once all the clams have opened, collect any spilled clam juice from the first baking sheet in a measuring cup.
When the clams are cool enough to handle, discard the top shells: Pick up a clam; holding the bottom shell and keeping the clam level, twist off the top shell. Arrange the opened clams on the baking sheet. Run a spoon underneath each clam to loosen it from its bottom shell. Distribute the reserved clam juice among the clams.
Melt the butter in an 8-inch skillet over medium heat. Add the bell pepper and shallot and cook, stirring occasionally, until softened, about 5 minutes. Stir in the wine and cook until the liquid is reduced by half, about 2 minutes. Remove the skillet from the heat and stir in the breadcrumbs, Parmigiano, parsley, and a few grinds of black pepper. (Do not season with salt.)
Spoon some of the breadcrumb mixture onto each clam. Top each with a tangle of bacon strips. Broil the clams until the topping is just browned, about 5 minutes. Serve with the lemon wedges or squeeze the wedges over the clams before serving.