1. Preheat oven to 350°. Bake pecans in a single layer in a shallow pan 5 to 7 minutes or until toasted and fragrant, stirring halfway through.
2. Prepare hot roll dough as directed on back of package; let dough stand 5 minutes. Roll dough into a 15- x 10-inch rectangle; spread with softened butter. Stir together brown sugar and cinnamon; sprinkle over butter. Sprinkle pecans over brown sugar mixture. Roll up tightly, starting at one long end; cut into 12 slices. Place rolls, cut sides down, in a lightly greased 12-inch cast-iron skillet or 13- x 9-inch pan. Cover loosely with plastic wrap and a cloth towel; let rise in a warm place (85°), free from drafts, 30 minutes or until doubled in bulk.
3. Preheat oven to 375°. Uncover rolls, and bake for 20 to 25 minutes or until center rolls are golden brown and done. Let cool in pan on a wire rack 10 minutes. Stir together powdered sugar, milk, and vanilla; drizzle over rolls.
Note: We tested with Pillsbury Specialty Mix Hot Roll Mix.