1 package pecan halves (6 ounces)
2-1/2 cups all-purpose flour
1 cup butter, at room temperature
3/4 cup light brown sugar, packed
1 teaspoon vanilla
1/2 teaspoon baking powder
Finely chop 1/2 cup pecans and set aside. Reserve remaining pecan halves for garnish. In a large bowl, mix chopped pecans, flour, and remaining ingredients until well blended and dough holds together.
Preheat oven to 350 degrees F. Between two sheets of waxed paper, roll half the dough 1/2 inch thick. With a 2-inch cookie cutter (any shape), cut dough into cookies. Gently move cookies to ungreased cookie sheet. Top with reserved pecan halves (one per cookie). Bake for 10 minutes, until lightly browned.