This is one of my very favorite appetizers, Dede! I've seen many different recipes over the years, but tend to just wing it when I make them for myself. Essential ingredients for me are butter, garlic, a mix of red and green bell pepper, parsley, lemon juice and (thin cut) bacon. I also top mine with a sprinkling of fresh breadcrumbs, but NEVER grated cheese (a few recipes call for it, and I just don't think it works).

If you are not making this as a spur of the moment snack, make the compound butter earlier in the day (or even the weekend before and freeze it). Here are my approximate ingredients:

For 2-3 dozen little or top neck clams
~ approx. 1/3-1/2 lb. bacon
~1-1/2 sticks unsalted butter, softened
~about 1/4 cup each of red and green bell pepper, cut in very tiny dice (1/4" tops)
~1 very fat clove garlic, or 2 smaller, smashed and minced to a fine pulp
~about 1 TBL FRESH lemon juice (or use 2 TBL dry white wine or dry white vermouth - you need something slightly acidic)
~2 TBL of finely minced Italian parsley
~some freshly ground black pepper
~breadcrumbs made with day-old bread, lightly toasted - 1/2 cup is probably enough (do not use packaged breadcrumbs)

Open clams, reserving juice. Loosen clam from it's shell where it's attached to make it easier to eat. Place clams in a single layer in a shallow oven-worthy baking dish (ideally, individual gratin dishes for each serving work best so that the juices from baking are kept in the pan for each guest - make sure you serve with bread!)

Strain clam juice to eliminate sand (I use a coffee filter, but a double layer of cheesecloth is the good old method).

Lightly cook the bacon so that it looks about halfway cooked (the microwave is great, or you can blanch it or saute). Dice into half-inch pieces.

Mix softened butter with remaining ingredients except breadcrumbs, mixing in the strained clam juice. Scoop a teaspoonful (you'll have to eyeball this, depending on the size of your clam) on top of each clam, sprinkle lightly with breadcrumbs, then top with a piece or two of bacon (depending on how you cut it).

Bake in a 400F oven for about 15 minutes - everything should be very hot and seriously bubbling and the bacon should have crisped.

Hope these inexact instructions aren't a problem! I love these so much that I've even concocted a "clams casino stuffed mushroom" appetizer to have when I don't have fresh clams and need a "fix" (using canned clams).