Tomato Butter Sauce
5 Comments Apr 24, 2024
Updated May 29, 2025
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This Tomato Butter Sauce comes together with just a few basics and turns out smooth, flavorful, and perfect for pasta night.It’s an easy staple to keep in your rotation.
You can make just about anything in the slow cooker. That’s why I had to try this tomato butter sauce. A handful of ingredients and a stick of butter simmer into a velvety, tomato-rich sauce—perfect for pasta night or beyond. Letting it simmer low and slow deepens the flavor.
The Magic Ingredients
The full ingredient amounts are in the recipe card.
- Whole Tomatoes – Canned and full of flavor, they break down beautifully in the slow cooker.
- Butter – Adds richness and helps mellow the acidity of the tomatoes.
- Onion – Quartered and tossed in, this infuses the sauce with subtle sweetness.
- Garlic Powder & Italian Seasoning – Brings classic Italian flavor.
Tips and Tricks
Crushed tomatoes are a great alternative to the whole ones if you want a less chunky sauce.
You can add additional vegetables such as mushrooms, leeks, celery or carrots.
Cut the butter in half if you’re concerned about calories.
Serving Suggestions
Toss this tomato butter sauce with al dente spaghetti or your favorite pasta for a comforting tomato butter pasta meal that’s ready in minutes.
Use this sauce as a base for homemade pizza, spreading it over a pre-baked crust and topping with your favorite cheese and toppings.
Serve this sauce alongside crusty bread for a simple yet satisfying appetizer that’s perfect for sharing.
Tomato Butter Sauce Recipe
Ingredients
- 56 oz. canned whole tomatoes, (two 28 oz. can tomatoes)
- ½ cup salted butter, (one stick)
- 1 white onion, peeled and quartered
- 1 tsp. garlic powder
- 1½ tsp. salt
- 2 tsp. Italian seasoning
Serving ideas
- serve on ravioli or noodles
Instructions
- Add everything to the slow cooker.
- Cook on low for 6 hours or on high for 4 hours. Stir once if you are home to incorporate the butter into the sauce.
- To serve, take a potato masher (or back of a wooden spoon) and crush the tomatoes. You can serve this with our without the onions if desired.
- Serve over your favorite pasta.
Sarah’s Notes
- Nutritional Values do not include pasta.
- Fresh tomatoes can be used instead of canned, though you will want to peel them. Do this by dropping in boiling water, remove and the skin should come right off.
- Store any leftover sauce in an airtight container in the refrigerator for up to 5 days, or freeze it for longer storage.
Nutrition
Nutrition info is auto-generated. This information is an estimate; if you are on a special diet, please use your own calculations.
More Slow Cooker Sauce Recipes
Try Slow Cooker Spaghetti Sauce for a classic, all-day simmered tomato sauce that’s perfect over pasta.
Make Nacho Cheese Sauce in the crockpot for a creamy, crowd-pleasing dip or topping for your favorite Tex-Mex dishes.
Slow Cooker Bolognese is a hearty meat sauce that slow cooks to rich, savory perfection—ideal for serving over spaghetti or rigatoni.
Since you mentioned “easy”, why not 2 cans of Pureed Tomatoes? Save time by not having to attack it with a potato masher.
Also, would this work with meatloaf or too buttery?
You could use pureed tomatoes; I like it a little chunky though. I think this would be good with meatloaf!
Couldn’t the onions be quartered and thickly sliced?
Yes, pretty much any way would work great.
I want MEAT with my.pasta so will include at least a pound of ground Beef or Pork….plus about 6 additional spices. And WHY whole tomatoes? Why not diced or sliced?