In a large mixing bowl, combine all-purpose flour, dried thyme, black pepper, and salt. If desired, mix in the optional baking powder and baking soda for lighter dumplings.

Create a well in the center and pour in the whisked eggs. Stir until a stiff dough forms; if it's too dry, gradually add milk until the dough is smooth and cohesive.

Bring a large pot of salted water to a gentle boil over medium-high heat. Scoop tablespoon-sized portions of the dumpling dough and carefully drop them into the bubbling water.

Cook for about 6-8 minutes or until the dumplings float to the surface, indicating they are cooked through. Remove them with a slotted spoon and set aside.

In a large pot, melt unsalted butter over medium heat. Add chopped onions and sauté until golden and fragrant, about 4-5 minutes.

Add the remaining butter and shredded cabbage to the pot with the cooked onions. Pour in the stock and sprinkle garlic powder, salt, and pepper to taste.

Stir everything together, cover, and let it simmer for 15-20 minutes or until the cabbage is tender.

Once the cabbage is tender, gently fold in the cooked dumplings. Toss together carefully, ensuring dumplings are coated without breaking.

Adjust seasoning if necessary. Transfer to a serving dish, garnish with freshly chopped parsley, and serve warm.