Iron Skillet Cinnamon Rolls

1 (18.25 ounce) box yellow cake mix (no pudding)
5 cups all-purpose flour
1 package dry yeast
2 1/2 cups warm water
1 1/2 cups (3 sticks) butter, room temperature
1/2 cup granulated sugar
1 1/2 cups firmly packed brown sugar, divided
1 cup pecan pieces
Cinnamon

In a large bowl, combine cake mix and flour.

In a small bowl, dissolve yeast in warm water. Add dissolved yeast to cake mix/flour mixture. Mix with wooden spoon and hands. Let rise in a warm place for about 1 hour.

On a well-floured surface, roll out dough to 1/2-inch thick. Using 1/2 cup butter, butter the dough.

Combine 1/2 cup granulated sugar, 1/2 cup brown sugar and cinnamon to taste. Sprinkle over buttered dough. Roll lengthwise and cut into 24 rolls.

Butter bottom and sides of two 10-inch cast iron skillets, using about 1/2 cup per pan. Sprinkle buttered skillets with remaining brown sugar and pecans. Put rolls in skillets and let rise 1 hour.