Step 1

Melt 1/4 cup of butter in a saucepan, and stir in the confectioners' sugar and corn syrup until the sugar is dissolved. Bring to a boil over medium heat, stirring often, and stir in the pecans until well combined. Refrigerate the mixture for 30 minutes to chill.

Step 2

Preheat oven to 350 degrees F (175 degrees C). Sift the flour and baking powder together in a bowl, and set aside.

Step 3

Beat brown sugar, 3/4 cup butter, egg, and vanilla extract in a large bowl with an electric mixer on medium speed until the mixture is creamy, about 2 minutes. Gradually beat in the flour mixture until well mixed. Pinch off about 1 tablespoon of dough, and roll it into a ball. Press the dough into the bottom of an ungreased cupcake pan cup, and use your thumb to press the dough into a small piecrust shape, with 1/4-inch walls up the sides of the cupcake cup. Repeat with the rest of the dough. Fill each little crust with about 1 teaspoon of the prepared pecan filling.

Step 4

Bake in the preheated oven until the cookie shells are lightly browned, 10 to 13 minutes. Watch closely after 10 minutes. Let the cookies cool in the cupcake pans for 5 minutes before removing to wire rack to finish cooling.