In a large mixing bowl,cream butter and cream cheese. Gradually add flour, beating until mixture forms a ball. Cover and refrigerate for 15 minutes.
For filling, in a small bowl, combine the brown sugar, eggs and butter. Set aside.
Roll dough into 48 balls. Press onto the bottom and up the sides of greased miniature muffin cups. Spoon a scant teaspoon of filling into each cup. Top each with a pecan half. Bake at 350 for 20-25 minutes or until golden brown. Cool 2-3 minutes before removing from pans to wire racks.