Add the uncleaned, meaty ham bone to a large Dutch oven along with the rinsed split peas, diced onions, onion powder, butter, olive oil, minced garlic, bay leaves, and thyme. Pour in the water and bring the mixture to a boil; once boiling, lower the heat to a gentle simmer, keeping the lid slightly ajar. Allow the soup to simmer for approximately 2½ hours, stirring occasionally to prevent sticking at the bottom. If you are cooking at a higher altitude, be aware that additional simmering time, potentially up to 5 hours, may be necessary. About 40 minutes before the soup finishes cooking, stir in the diced carrots and potatoes. When the vegetables are fork-tender, remove the ham bone, bay leaves, and thyme stems. Carve or shred 2 cups of ham from the bone and return it to the pot. Serve warm and enjoy.