Bring a large pot of salted water to boil and add pasta, cooking until al dente (about 10 minutes). Reserve 1 cup pasta water before draining—this starchy liquid becomes your sauce's secret weapon for silky texture and helps everything come together.

While pasta cooks, heat olive oil and butter in a large skillet over medium-high heat. Add diced onion and sauté for 3 minutes until softened, then add minced garlic and cook for 1 minute until fragrant and golden.

Season chicken pieces with salt and Italian seasoning, then add to the skillet in a single layer. Sear for 5 minutes per side until golden brown, ensuring the chicken cooks through completely before moving forward.

Pour in crushed tomatoes and chicken broth, stirring well to combine with the browned bits at the skillet's bottom. Reduce heat to medium and simmer for 8 minutes, allowing flavors to meld while the chicken finishes cooking.

Stir in heavy cream and sugar, whisking gently to create a cohesive sauce for your cozy weeknight pasta dinner recipe. Add reserved pasta water one splash at a time until the sauce reaches your desired consistency—it should flow like silk.

Add drained pasta directly to the skillet and toss constantly for 2 minutes, ensuring every strand gets coated with the creamy sauce. The heat will help everything incorporate beautifully into that heartwarming comfort you're craving.

Fold in fresh basil gently, tasting and adjusting seasoning as needed with additional salt and pepper. Divide among bowls immediately and top each serving with grated Parmesan cheese for that finishing touch.