Pour warm water into a bowl; add yeast and let stand until creamy, about 10 minutes.

Combine yeast mixture, cake mix, and 3 cups of flour in a large bowl; stir well. Add remaining flour, 1/2 cup at a time, stirring well after each addition until dough pulls together. Knead until smooth and elastic, about 8 minutes.

Lightly oil a large bowl; place dough in the bowl and turn to coat with oil. Cover with a damp cloth and let rise in a warm place until doubled in volume, about 30 minutes.

Deflate dough and roll it into a 10x16-inch rectangle. Spread softened butter over the rectangle; sprinkle on brown sugar and cinnamon. Roll up the rectangle and cut into 1-inch wide rolls.

Preheat the oven to 375°F (190°C). Grease a 9x13-inch baking pan.

Dip the top of each roll in melted butter, then in sugar and pecan mixture, then arrange rolls snugly in the prepared pan. Cover rolls and let rise until doubled in volume, about 30 minutes.