Ravioletto

Mound flour in center of a large work surface, and make a well in the middle. Add salt and egg yolks.

Using a fork, beat eggs; slowly incorporate flour, beginning with inner rim of well, adding 1/3 cup water, little by little, until dough is soft. When flour is incorporated, gather dough together to form a rounded mass. Begin kneading dough with the palms of your hands. Once dough comes together, scrape up any dried bits of dough; discard.

Lightly flour work surface; knead dough until smooth and elastic. Wrap in plastic wrap and refrigerate for 1 hour.

Set the rollers of a hand-crank or electric pasta machine at their widest opening. Divide dough into 6 pieces. Working with 1 piece of dough at a time, being sure to keep remaining dough covered, flatten dough with the palms of your hands and run it once through the machine. Fold the dough in half, sprinkle with flour, and run through the machine again. Repeat this step about 6 times, until the dough is smooth and elastic.

Now change the rollers of the pasta machine to the next decreasing setting, and roll out the dough once without folding. Keep rolling the sheet through the machine on decreasing settings, adding flour if necessary, until you have rolled it through the last (thinnest) setting.

Place pasta sheet on work surface and let stand 5 minutes. Using a sharp knife or pastry wheel, cut pasta into four 5-by-5-inch squares. Transfer squares to a lightly floured work surface and set aside, covered, until ready to use. Repeat process with remaining pieces of dough.

Bring a large pot of lightly salted water to a boil. Prepare an ice-water bath. Cut out twenty-four 7-by-7 1/2-inch rectangles out of parchment paper; butter parchment using 1/4 cup butter and set aside.

Add pasta squares to boiling water and cook until al dente, 1 to 2 minutes. Using a slotted spoon, transfer pasta to ice-water bath to cool. Drain immediately and lay pasta squares flat on a dry cloth, taking care not to overlap.

Preheat oven to 375 degrees.

Cut the crescenza cheese into twenty-four 2-by-2-by-1/4-inch pieces. Place one piece of cheese in the middle of each pasta square. Fold the bottom and top flaps of the pasta over the middle (like a letter), then fold the sides over the top and bottom flaps to enclose. Place each ravioletto, seam-side down, in the middle of a piece of buttered parchment. Fold long sides of parchment over the middle (like a letter), then fold the short sides over the long sides to enclose. Place parchment paper packet, seam-side down, on a baking sheet (at this point, ravioletto may be frozen for up to 1 month. Bake directly from freezer for 25 minutes and continue with step 10). Transfer baking sheet to oven and bake until edges of parchment are barely golden brown, 10 to 12 minutes.

Meanwhile, in a medium saucepan, melt remaining 1 1/2 cups butter over medium heat. Cook until nutty brown in color, 4 to 6 minutes, taking care not to burn.

In a small skillet, heat olive oil over medium-high heat. Add garlic and cook until crisp. Transfer garlic to a paper towel-lined plate to drain.

Place 1 tablespoon Parmigiano-Reggiano cheese in the center of each of 12 warmed plates. Carefully remove ravioletto from parchment paper packets; arrange 2 ravioletto on each plate and sprinkle with another tablespoon Parmigiano-Reggiano cheese. Garnish with garlic, rosemary, and flower petals, if using. Serve immediately.