Line twenty-four 1 3/4-inch muffin cups with paper bake cups; set aside. In a small saucepan, melt butter and chocolate over low heat.

Remove from heat; transfer to medium bowl. Add the eggs, granulated sugar, vanilla, and salt. Beat lightly with a wooden spoon just until combined.

Stir in flour and pecans. Spoon a rounded tablespoonful of batter into each prepared muffin cup.

Bake in a 350°F oven about 20 minutes or until toothpick inserted in centers comes out clean. Cool in muffin cups on wire rack for 5 minutes. Remove from cups; cool completely. Sprinkle tops with powdered sugar.

Makes 24 muffins.