Peanut butter-chocolate sandwich cookies

These may well be the easiest, and tastiest, peanut butter-chocolate cookies around. There's just five ingredients in the cookie, with no butter or flour, and the filling is simply bittersweet chocolate and butter. Yum. The recipe is from Fine Cooking. Instead of making regular-sized cookies, I made mine about large-quarter-sized. This turned out to be just right, as they're quite rich, and this way you can kinda sorta justify having another.

Peanut Butter & Chocolate Cookies
(makes about 30 regular sandwich-sized cookies. I made large quarter-sized cookies and ended up with about 50 cookies)

Cookies:
2 1/2 c smooth peanut butter
1 1/2 c brown sugar, packed
1 tsp baking soda
2 eggs
2 tsp vanilla

Filling:
10 oz bittersweet chocolate (I used Ghirardelli bittersweet chips, the whole bag. Or you could use semisweet chips for a slightly sweeter filling)
8 Tbs unsalted butter

Preheat oven to 350 degrees.

In a bowl, mix peanut butter, brown sugar, and baking soda together til smooth. Add the eggs and vanilla, and mix til just blended.

Roll tablespoonfulls of dough into balls (or for me, scant teaspoonfulls). Arrange the balls about 1.5 inches apart on a cookie sheet (or less for smaller cookies). Do not press down. Bake one cookie sheet at a time (yes, this takes longer, but it makes a difference), until the cookies are puffed and crackled but still moist-looking, 11 min. (or about 9 min. for smaller). Transfer the cookie sheets to a rack to cool for about 10 min., then transfer the cookies to another rack to cool completely. Repeat for the remainder of the dough.

Meanwhile, melt the chocolate and butter in a double boiler 'til smooth. Remove from the heat and set aside til smooth and slightly thickened (like peanut butter consistency), 20 to 30 min.

Fill the cookies ... about 2 tsp per cookie for half of the cookies. Top each with another cookie, and let set for about 30 min.