Recipe came from The Baking Sheet, Winter 2007 edition, a newsletter published quarterly (I think) by the people who make King Arthur Flour.
These things taste great, and are really easy. Once you try 'em, you'll never be able to buy a box of Nilla Wafers again, because they'll taste like sawdust. If you ever make banana pudding, use these instead.
The commentary accompanying the recipe says there are "...terrific as they are (or sandwiched together with a bit of chocolate while still warm), they'd also make a terrific crust for a banana or chocolate cream pie."
1-1/2 cups unbleached all-purpose flour
1/2 teaspoon salt
1 teaspoon baking powder
1/3 cup unsalted butter
1/3 cup vegetable shortening (non-trans fat preferred)
1 cup sugar
2 teaspoons vanilla extract
1 large egg
2 tablespoons milk
Preheat oven to 350. Lightly grease, or line with parchment, 2 baking sheets. (I used non-stick sheets, didn't grease them, and the wafers came out fine.)
In a medium bowl, whisk together the flour, salt, and baking powder; set aside.
In a large bowl, cream together the butter and shortening. Gradually add the sugar with the mixer running at medium speed. Beat until the mixture is light and fluffy, stopping to scrape the sides and bottom of the bowl after all of the sugar is incorporated.
Add the vanilla and the egg, and beat once again until the mixture is uniform.
Mix in half of the flour, scrape the bowl, and add 2 tablespoons of milk. Mix in the remaining flour until the dough is smooth.
Scoop by teaspoonfuls onto the prepared baking sheets; bake for 12-14 minutes, until the edges are brown.
Yield: 4-1/2 dozen cookies (I don't think I got nearly this many, probably more like 3 dozen).