In a small bowl, mix together 1/4 cup mayonnaise and yogurt. Season with curry powder, chile pepper, and garlic powder. Stir in the mango chutney. Cover and chill at least 30 minutes.
In a separate bowl, toss together the green onion, jalapeno, garlic, bread crumbs, and 1/2 the crackers. Mix in the egg, 1/2 cup mayonnaise, mustard, Worcestershire sauce, lemon juice, and Old Bay seasoning. Fold in the crabmeat. Form the mixture into 6 cakes and evenly coat with the remaining bread crumbs.
Heat the olive oil in a skillet over medium-high heat. Cook each cake about 5 minutes on each side, until heated through and golden brown. Serve with the chilled sauce mixture.