Stir together 2 1/2 cups flour and the yeast in a large bowl. Add warm milk, 2 tablespoons melted butter, sugar, and salt. Stir in 3 1/4 cups flour.
Turn dough out onto a lightly floured surface; knead until smooth and elastic, adding up to 3/4 cup additional flour if dough is sticky, 8 to 10 minutes. Shape dough into a ball. Transfer to a large greased bowl, turning to coat. Let rise, covered, in a warm place until doubled in size, 1 hour.
Turn dough out onto a lightly floured surface. Let stand, covered, 10 minutes. Line 2 or 3 large baking sheets with parchment paper. Portion dough into 30 (1 1/2-ounces) pieces. Roll each piece into a 8-inch log; arrange on prepared baking sheets. Let rise, covered, 30 minutes.
Preheat the oven to 375 degrees F (190 degrees C). Combine remaining 8 tablespoons melted butter and garlic salt in a small bowl. Brush dough with half of the butter mixture.
Bake in the preheated oven until puffed and an instant-read thermometer inserted into centers registers 210 degrees F (98 degrees C), about 10 minutes. For a richer, golden-brown color, bake an additional 5 minutes. Brush with remaining butter mixture. Sprinkle with Parmesan (if using). Serve warm.
