In a large skillet or dutch oven cook bacon over medium-high heat until crisp. Remove to paper towels to drain using a slotted spoon, reserving 4 Tbsp drippings in skillet.
To the drippings add onion. Saute over medium-high for 3 minutes or until beginning to brown then add garlic and fennel seed, if using. Saute for 1 minute.
Add cabbage to skillet. The skillet will be full but, the cabbage will shrink as it cooks. Once it begins to shrink, add salt, onion powder, granulated garlic, pepper flakes and black pepper. Mix well.
Cook over medium heat stirring occasionally until cabbage has softened and is browning, about 15-20 minutes.
Crumble bacon and add back to the cabbage or use to garnish the top.
Serve and enjoy.