This 4-ingredient oven gemelli is the kind of weeknight recipe I lean on when I’m tired, hungry, and not in the mood to babysit a pot on the stove. You literally throw dry gemelli pasta into a square glass baking dish, add three pantry-friendly “secret” ingredients—jarred marinara, water, and a generous blanket of shredded mozzarella—and let the oven do the work. Baked pasta dishes like this trace their roots to Italian-American home cooking, where families found smart ways to turn dry pasta and tomato sauce into hearty, hands-off casseroles. The result is a bubbling, saucy, cheesy dish that tastes like you fussed, even though you barely lifted a finger.
Serve this oven gemelli straight from the glass baking dish with a simple green salad dressed in a sharp vinaigrette to cut through the richness, and warm crusty bread or garlic toast for scooping up the extra sauce. A side of roasted vegetables—broccoli, zucchini, or green beans—roasts nicely on the rack below while the pasta bakes. If you enjoy wine, a light red such as Chianti or a medium-bodied Pinot Noir pairs well with the tomato and cheese, while sparkling water with lemon keeps things refreshing for a family-friendly table.
4-Ingredient Oven Gemelli
Servings: 4

Ingredients
8 ounces dry gemelli pasta
2 cups jarred marinara sauce
2 cups hot water
2 cups shredded low-moisture mozzarella cheese, divided
Directions
Preheat your oven to 400°F (200°C). Place a clean, 8x8-inch square glass baking dish on the counter. This is both your mixing bowl and your baking pan.
Pour the dry gemelli pasta evenly into the square glass baking dish, spreading it into a fairly even layer so it cooks uniformly. This should look just like that top-down, in-progress shot: uncooked pasta scattered across clear glass.
In a large measuring cup or bowl, whisk together the jarred marinara sauce and the hot water until the mixture is smooth and pourable. Using hot (not boiling) water helps the pasta start to soften more quickly in the oven.
Pour the marinara-water mixture evenly over the dry gemelli in the glass dish. Use a spoon to gently press the pasta down so most of it is submerged in the liquid. It’s fine if a few pieces peek above the surface; they’ll soften as they bake.
Sprinkle 1 1/2 cups of the shredded mozzarella evenly over the top of the sauced pasta. Reserve the remaining 1/2 cup of mozzarella for later. The cheese will melt down into the sauce as it bakes, helping to create a creamy, cohesive texture.
Cover the square glass baking dish tightly with aluminum foil, crimping the edges to seal in steam. This step is important: the trapped steam cooks the dry pasta through without boiling it first.
Place the covered dish on the middle rack of the preheated oven and bake for 30 minutes. During this time, avoid opening the oven so the heat and steam stay consistent.
After 30 minutes, carefully remove the dish from the oven and peel back the foil away from you to avoid steam burns. Stir the pasta thoroughly, scraping the corners and bottom to release any bits that may have settled. The pasta should be mostly tender but still slightly firm in the center.
Sprinkle the remaining 1/2 cup of mozzarella evenly over the top of the pasta. Return the dish to the oven, uncovered, and bake for another 10–15 minutes, or until the cheese is melted, lightly browned in spots, and the sauce is bubbling around the edges.
Remove the baking dish from the oven and let the gemelli rest for 5–10 minutes before serving. This short rest allows the sauce to thicken slightly and makes the pasta easier to scoop into neat portions. Taste and, if you like, finish with a light pinch of salt at the table.
Serve the baked gemelli directly from the glass dish, making sure each portion gets a good mix of saucy pasta and browned, cheesy top. Your husband—and anyone else at the table—will likely be back for seconds.
Variations & Tips
For extra flavor without adding more ingredients, choose a robust marinara with garlic, basil, or roasted vegetables already in the jar; the sauce does most of the seasoning work here. If you want a creamier version, swap 1/2 cup of the hot water for 1/2 cup of half-and-half or whole milk, then mix that with the marinara before pouring over the pasta. To add protein, scatter 1–1 1/2 cups of cooked Italian sausage, rotisserie chicken, or meatballs (cut into small pieces) over the pasta before adding the first layer of cheese. For a spicier take, use a spicy arrabbiata sauce or serve with crushed red pepper flakes at the table. If you prefer a bit of crunch, top the final layer of mozzarella with 1/4 cup of seasoned breadcrumbs before the last bake. Food safety tips: Use an oven-safe glass baking dish (check the manufacturer’s markings on the bottom). Avoid placing a cold glass dish directly into a very hot oven; if your dish is chilled, let it come to room temperature first to reduce the risk of thermal shock. Always handle the hot glass pan with dry oven mitts and place it on a trivet or dry towel—never on a wet or cold surface. Leftovers should be cooled, then refrigerated within 2 hours and eaten within 3–4 days; reheat until steaming hot in the center before serving.