Preheat oven to 180 degrees C. Grease and flour 18 mini muffin cups or line with patty cups.
In a medium bowl, stir together brown sugar, flour and pecans. In a separate bowl beat the butter and eggs together until smooth, stir into the dry ingredients just until combined. Spoon the batter into the prepared muffin cups. Cups should be about 2/3 full.
Bake for 20 to 25 minutes. Cool on wire racks when done.