To make Minted Yogurt: Combine yogurt, mint and 1 clove garlic in small bowl, and season with salt and pepper, if desired. Chill 1 hour.
To make Latkes: Heat 2 Tbs. oil in Dutch oven or large pot over medium-high heat. Add onion, and sauté 5 to 7 minutes, or until golden brown. Add garlic, curry powder, cumin, and ginger; sauté 30 seconds. Add cauliflower and 2 cups water; season with salt and pepper, if desired. Cover, and bring to a simmer. Reduce heat to medium-low, and simmer 20 minutes, stirring occasionally and breaking up florets with spatula or spoon. Uncover, and cook 20 to 30 minutes more, or until all liquid has evaporated. Coarsely mash with potato masher, and cool.
Whisk together egg and mayonnaise in bowl. Stir in cauliflower mixture; fold in crushed matzo, raisins, and cornstarch. Season with salt and pepper, if desired.
Heat remaining 1/4 cup oil in large nonstick skillet over medium heat. Transfer 1/4-cup scoops of cauliflower mixture into skillet, flattening each scoop to 2 1/2 inches in diameter. Fry 4 minutes on each side, or until browned. Repeat with remaining cauliflower mixture, adding more oil to pan as needed. Drain on paper towels. Garnish Latkes with mint sprigs and chiles (if using), and serve with Minted Yogurt.