Holding the clam shell over a large bowl and using a heavy spoon, break the shell, being careful to capture the liquid or juice in the bowl. Remove the meat and add it to the bowl. “Wash” the clams in the juice to remove any sand, and then put them in the bowl of a food processor. Carefully pour or strain the remaining juice into a clean bowl, making sure that any sand or shell is discarded.

Add the onion, jalapeño and garlic and process about 10 seconds. Add the flour, baking powder, ½ cup of the clam juice, salt and pepper and process again into a smooth batter. Add more clam juice if necessary.

Pour enough oil into a shallow pan to cover the base ½-inch deep. Heat over medium-high heat to about 350°F. When hot, carefully drop spoonfuls of the batter into the oil and cook, turning once, until golden brown, about 3 minutes on each side. Transfer to a wire rack to drain. Serve hot.