This slow cooker 3-ingredient ketchup butter spaghetti is the exact kind of sweet, tangy, glossy “paycheck’s not here yet” meal my brother swears by. It’s pure pantry cooking: dry spaghetti, a squeeze-bottle of ketchup, and a stick of butter come together in the slow cooker to make a shockingly addictive, sticky red sauce that clings to every strand. It’s not fancy, it’s not traditional Italian, but it absolutely hits the spot when money, time, and energy are all running low—and you still want something warm and comforting in a big bowl.
Serve this spaghetti piled high in shallow bowls or on plain white plates so you can really see that shiny red-orange sauce. Because it’s rich and sweet, I like to balance it with something crisp and simple on the side—like a basic green salad with bottled Italian dressing or some frozen mixed veggies quickly steamed in the microwave. Garlic bread, toast, or even plain buttered white bread is great for swiping up the extra sauce. If you have it, a sprinkle of black pepper or red pepper flakes on top helps cut through the sweetness and makes it feel a little more “grown-up” while still being a total budget comfort meal.
Slow Cooker 3-Ingredient Ketchup Butter SpaghettiServings: 4
Ingredients
16 ounces (1 pound) dry spaghetti
1 1/2 cups ketchup
1/2 cup (1 stick, 4 ounces) unsalted butter, cut into chunks
4 cups hot water (or enough to just cover the spaghetti in your slow cooker)
Directions
Lightly grease the inside of your slow cooker crock with a small swipe of butter or a bit of cooking spray if you have it. This helps keep the spaghetti from sticking too much as it cooks.
Break the dry spaghetti noodles in half so they fit more easily in the slow cooker. Scatter them in an even layer (or as even as you can) across the bottom of the crock.
Pour the ketchup evenly over the dry spaghetti. Don’t worry if it looks like a lot or if it doesn’t coat every strand yet—the sauce will loosen and spread as it cooks.
Add the butter chunks on top of the ketchup and pasta, spreading them around so they’re dotted over the surface. This is what will melt down and give you that glossy, rich, almost sticky sauce.
Pour in enough hot water to just cover the spaghetti. In a standard 5- to 6-quart slow cooker, this is usually about 4 cups, but add it slowly and stop once the noodles are mostly submerged. Gently press the pasta down with a spoon to make sure everything is in contact with the liquid.
Cover the slow cooker with the lid and cook on HIGH for 1 1/2 to 2 hours, or on LOW for about 3 hours. Around the 1-hour mark (or halfway through on LOW), open the lid and use tongs to gently toss and separate the noodles, making sure the ketchup and melted butter start coating everything. This helps prevent clumping and ensures more even cooking.
Check the spaghetti for doneness starting at about 1 1/2 hours on HIGH (or 2 1/2 hours on LOW). The pasta should be tender, soft, and fully cooked through, with most of the liquid absorbed into a thick, glossy red sauce clinging to the noodles. If it looks too watery, cook with the lid slightly ajar for another 10–15 minutes, tossing occasionally, until the sauce thickens and looks shiny and sticky.
Once the spaghetti is tender and the sauce is thick and glossy, give it a final toss to coat every strand in the ketchup-butter mixture. Taste and, if you want it sweeter or tangier, you can squeeze in a little extra ketchup and toss again.
Serve immediately, twirling generous portions of the spaghetti onto plates or into bowls so you get those long, tender strands completely covered in the bright red, buttery sauce. This is best eaten hot, right after cooking, when the texture is at its glossiest and most comforting.
Variations & Tips
To keep the spirit of a true 3-ingredient poverty meal, the base recipe stays exactly as written, but you can tweak it when you have a little extra wiggle room. For a slightly less sweet version, use a mix of ketchup and canned tomato sauce or crushed tomatoes in place of some of the ketchup. If you like a little heat, add a pinch of red pepper flakes or black pepper when serving. A spoonful of mustard or a splash of vinegar stirred in at the end will give more tang and balance the richness. When your budget allows, you can dress this up with a shower of grated Parmesan, a handful of shredded cheese, or some frozen peas or corn stirred in during the last 15 minutes of cooking. Leftovers reheat well in the microwave with a small splash of water to loosen the sauce—just cover and heat in short bursts, stirring between each, until hot and glossy again.
