Put diced bacon in a cold skillet and heat over medium-high heat. Cook bacon, stirring occasionally until crispy, about 10 minutes. Remove bacon bits from pan and grease and let drain on a paper towel lined plate.
Meanwhile, cook pasta according to package directions.
Remove most of the bacon grease from the skillet, reserving about 1 TB in the pan. Return the pan to heat and put in frozen peas and butter. Let the peas heat through and defrost, about 3 to 5 minutes. Once peas are defrosted add in the garlic and sautee 1 minute.
Stir in salt and heavy cream. Pour cooked spaghetti noodles into the skillet and toss to coat. Stir in parmesan cheese.
Serve hot topped with crisp bacon.
Notes
***Note: I keep the bacon separate to keep it crisp. If you toss it with the wet ingredients then they'll start to soak in that liquid. I like my bacon crisp and I love the added crunch.