How to Make It
Sift the flour and salt in a large bowl.
In a small bowl, whisk the yeast into the water and let sit for about 5 minutes, until bubbling. Whisk in 3 tablespoons of the olive oil. Using a rubber spatula, make a well in the center of the flour. Pour in the yeast mixture and stir in a circular motion with the spatula, incorporating more flour as you stir. Drop the spatula and use your hands to knead the dough, making sure the dough is smooth and there are no dry bits of flour at the bottom of the bowl. Transfer the dough to a large, clean bowl greased with oil. Cover with lightly oiled plastic wrap and let rest in a warm spot until it doubles in size, 1 to 2 hours, depending on the temperature of the room.
Meanwhile, heat the remaining 2 tablespoons olive oil in a large skillet over medium heat. Add the sausage and cook, stirring frequently, until crisp, 8 to 10 minutes.
Drain the sausage in a plate covered with paper towels and let cool completely.
Invert the dough onto a floured surface and press it down to deflate. Divide the dough into 3 equal pieces. Working with one piece at a time, roll the dough out into a slightly rounded rectangular shape of about 14 by 8 inches, distribute a third of the sausage over it, and sprinkle with a few rosemary leaves. Starting at the far end of the dough, roll it toward you, jelly-roll style, pinching the edges when you get to the end. Roll out the second piece of dough and spread another third of the sausage all over, followed by some rosemary leaves. Now, before you continue, place the first rolled piece of dough on top of the second piece of dough, toward the start, and roll it up around the first piece. Repeat with the third piece, placing the previous 2 rolls inside. By the time the 3 pieces of dough are stuffed and rolled, you will have a jelly-roll shape of about 3½ inches in diameter. Trim both ends.
Grease an 8-cup tube pan with vegetable oil. Fit the dough inside the prepared pan, seam side up. (If the length of the dough is longer than that of the mold, you can overlap. If it’s shorter, bring the dough back to the work surface and stretch it.) Cover with oiled plastic wrap and let rise until doubled in size, 1 to 2 hours (or refrigerate overnight). When risen, the dough will be about 1 inch above the rim of the pan.
When the dough is almost risen, preheat the oven to 425°F and set a rack in the lower third of the oven.
Bake until the bread is golden and firm, and the internal temperature is about 200°F, about 30 minutes. Transfer the pan onto a wire rack and let it cool in the pan for about 10 minutes before unmolding. Use a serrated knife to cut it into thick slices.