In a small bowl, dissolve 1 teaspoon sugar and yeast in lukewarm water. Let stand until foamy, about 10 minutes. Warm the milk in a small saucepan until it bubbles, then remove from heat. Mix in 1/4 cup sugar, 60g butter and salt, and stir until melted. Let cool until lukewarm.
In a large bowl, combine the yeast mixture, milk mixture, eggs and 1 1/2 cups flour; stir well to combine. Stir in the remaining flour, 1/2 cup at a time, beating well after each addition. When the dough has pulled together, turn it out on to a lightly floured surface and knead until smooth and elastic, about 8 minutes.
Lightly oil a large bowl, place the dough in the bowl and turn to coat with oil. Cover with a clean, damp cloth and let rise in a warm place until doubled in volume, about 1 hour.
While dough is rising, melt 170g butter in a small saucepan over medium heat. Stir in 3/4 cup brown sugar, whisking until smooth. Pour into greased 23x33cm baking tin. Sprinkle bottom of pan with half the pecans and set aside. Melt remaining butter; set aside. Combine remaining brown sugar, pecans and cinnamon; set aside.
Turn dough out on to a lightly floured surface and roll into an 45x35cm rectangle. Brush with half the melted butter, leaving a 1cm border uncovered. Sprinkle with the cinnamon sugar mixture. Starting at the long edge, tightly roll up, pinching seam to seal. Brush with remaining melted butter. With a serrated knife, cut into 15 pieces. Place, cut side down, in prepared pan. Cover and let rise for 1 hour or until doubled in volume. Meanwhile, preheat oven to 190 degrees C.
Bake for 25 to 30 minutes, until golden brown. Let cool in pan for 3 minutes, then invert on to serving platter. Scrape remaining filling from the pan on to the rolls.