Rinse and sort split peas to remove debris.
In a large pot, sauté onions, celery, and carrots until softened.
Add minced garlic and cook for 1 minute until fragrant.
Stir in the split peas, broth, diced ham, thyme, and bay leaf.
Bring the mixture to a boil, then reduce heat to low and cover.
Simmer for 60 to 90 minutes, stirring occasionally, until peas are soft and soup has thickened.
Remove the bay leaf.
Whisk in the unflavored protein powder or collagen until fully incorporated.
Season with salt and pepper to taste before serving.