Preheat the oven to 350°F. In a medium bowl, combine 4 tablespoons of the butter and 1/4 cup of the brown sugar with the flour and pinch into moist crumbs. Stir in the pecans.
1 1/2 sticks (6 oz) unsalted butter1 cup packed dark brown sugar1/2 cup all-purpose flour1/2 cup pecan halves