Combine 2 teaspoons of the garam masala, turmeric, garlic, ginger, and jalapeno in a blender with 4 tablespoons of water; puree in to a paste. Set aside.
In a large skillet, combine the oil, mustard seeds, coriander, cumin, chile and cinnamon stick. Place over medium-high heat and cook, stirring, until fragrant and the cinnamon stick unfurls, about 2 minutes. Add the onion and cook, stirring occasionally, until lightly browned, about 6 minutes. Add the reserved ginger paste and cook, stirring, until caramelized, about 5 minutes more.
Add the cabbage, the sugar (if using) and 2 tablespoons of water and cook, covered and stirring occasionally, until tender, 13 to 15 minutes. Uncover, season with salt, and cook, uncovered, until lightly browned, about 5 to 7 minutes more. To serve, remove the chile and cinnamon stick, sprinkle with the remaining 1 teaspoon garam masala and garnish with the cilantro.