Combine granulated sugar and cinnamon in a small bowl.
Dip marshmallows in melted butter, and roll in cinnamon mixture.
Separate crescent rolls into 16 triangles. Wrap 1 marshmallow with 1 triangle, pinching edges to seal. Repeat with remaining marshmallows and triangles. Place each roll in a lightly greased muffin pan cup.
Bake at 375° for 10 to 15 minutes or until golden.
Stir together powdered sugar and milk to form a smooth glaze. Drizzle over warm rolls; sprinkle with pecans, if desired.