In a large bowl, whisk together 1 ½ cups of bread flour, sugar, salt and instant yeast. Stir in warm water and oil and beat until smooth. Stir in enough remaining flour, ½ cup at a time, to form a soft dough. It should come together in a ball.
In a stand mixer fitted with the dough hook or on a floured surface, knead the dough until elastic and smooth, about 6-8 minutes.
Transfer the dough to a lightly oiled bowl and cover with plastic wrap. Let rest in a warm place until doubled in size, about 1 ½ - 2 hours.
Cut the dough into 12 equal pieces. Knead each piece slightly and shape into a 7-inch-long breadstick. Arrange the breadstick dough 2 inches apart on parchment-lined baking sheets. Cover with plastic wrap; let rise in a warm spot until puffy and almost doubled, about 1 hour.
Preheat the oven to 400° F.
Remove cover and bake the breadsticks until they’re a light golden brown, about 12-15 minutes. Meanwhile, combine the salt and garlic powder. Immediately brush the warm breadsticks with melted butter and sprinkle with the garlic and salt.