Combine ¼ cup warm water (105–110°F), 1 tsp sugar, and the yeast in a small bowl. Stir gently and let sit for 5–10 minutes until foamy and bubbly.
In a stand mixer bowl or large mixing bowl, combine the flour and salt, then add the yeast mixture, 1 tbsp olive oil, 1½ tbsp rosemary, black pepper (if using), and remaining ¾ cup warm water. Mix until a shaggy dough forms, adding warm water 1 tbsp at a time if too dry.
Using a stand mixer with dough hook, knead on medium speed for 8–10 minutes until smooth and elastic; by hand, knead on a lightly floured surface for 10–15 minutes. Dough is ready when it passes the windowpane test — a small piece stretches thin without tearing.
Place dough in a lightly oiled bowl, turn to coat, and cover with plastic wrap or a damp kitchen towel. Let rise in a warm, draft-free spot for 1 to 1½ hours, until doubled in size.
Punch down the risen dough, divide it into two equal portions, and shape each into a smooth oval loaf roughly 8–10 inches long with the seam on the bottom. Place on a parchment-lined baking sheet drizzled with olive oil.
Leave the loaves uncovered and let rise for 45 minutes to 1 hour until visibly puffier. Preheat oven to 400°F (200°C) during the last 15 minutes of this rise.
Bake the loaves in the center of the preheated oven for 10 minutes to set the structure, then remove from the oven (keep oven on).
Brush the tops of both loaves generously with olive oil, then sprinkle with kosher salt and the remaining ½ tbsp dried rosemary, pressing lightly to adhere. Return to the oven and bake another 10–15 minutes until deep golden brown and hollow-sounding when tapped on the bottom.
Transfer loaves to a wire rack and rest for 5–10 minutes. Serve warm with a shallow dish of extra virgin olive oil seasoned with freshly ground black pepper for dipping.