Peel and slice onions to about 1/8-inch thick — thin enough to cook quickly, thick enough to avoid scorching. Yellow or Spanish onions work best. Limit to 2 large onions per 12-inch Skillet to prevent steaming. Have your fat ready and keep a splash of water, broth, or wine nearby to deglaze if needed.

Heat a Skillet over medium to medium-high heat. Add butter, oil, or a mix and let it shimmer. Add sliced onions in large handfuls, stirring for 1–2 minutes per batch until they begin to soften — this prevents overcrowding. Once all onions are in, season with a pinch of salt. Cook over medium heat, stirring every few minutes, for 8–12 minutes total until soft, translucent, and lightly golden. To speed up softening, add 1/4 to ½ cup water or broth and cover; steam wilts the onions in a few minutes. Remove the lid once liquid evaporates and continue cooking uncovered. If the pan looks dry, deglaze with a splash of water, broth, or wine, scraping up any browned bits. Don't crank the heat — high heat burns the outside before the onions cook through.

Pour in the ½ cup vodka and stir, scraping up any bits from the bottom of the pan. Let it simmer for 2–3 minutes until the alcohol smell mellows. Add the crushed 1 can whole peeled San Marzano tomatoes crushed by hand, 1 tsp 1 tsp kosher salt plus more for pasta water, and ½ tsp freshly ground black pepper. Stir to combine and simmer over medium-low heat for 10 minutes, stirring occasionally, until the sauce thickens slightly.

Reduce the heat to low and stir in the Heavy Cream. Simmer gently for 3–4 minutes until the sauce turns a deep blush-orange color. Add the drained Penne Pasta directly to the Skillet and toss to coat. Splash in pasta water a little at a time until the sauce is glossy and clings to the pasta. Remove from heat and stir in the grated Parmesan Cheese until melted. Taste and adjust seasoning. Serve immediately topped with fresh Basil and extra Parmesan Cheese.