In a food processor, pulse the ginger until finely chopped. Add the 3/4 cup cashews; process until smooth, 2 to 3 minutes.
Add the yogurt, cilantro, sugar, and curry powder; season with salt. Process until incorporated, 1 to 2 minutes, scraping down the sides as needed. Transfer to a serving bowl; sprinkle with the remaining cashews.
Season the shrimp with salt and pepper. Heat 1 tablespoon of the oil in a large nonstick skillet over medium-high heat. Add half the shrimp; cook until opaque throughout, 2 to 3 minutes. Repeat with the remaining tablespoon oil and remaining shrimp. Serve the shrimp with the sauce.