Cook bacon by baking it, in a skillet, or using microwave bacon. Dab off grease then dice finely.
In a large bowl, whisk together mayo, sour cream, vinegar, Dijon, sugar, garlic powder, salt, and pepper until smooth.
Add thawed and dry peas, red onion, cheese, parsley, and cooled bacon to a large bowl. Add dressing on top and gently stir to combine. Taste and adjust seasoning if needed.
Cover and refrigerate for 15-20 minutes for flavors to meld or serve immediately if needed.
Video
Notes
Storage: For the best flavor and texture, add the bacon and red onion just before serving (bacon softens and the onion flavor can take over). Store leftovers in an airtight container in the fridge for up to 3 days. Stir before serving.