Combine sweet potatoes and 1/4 cup evaporated milk in food processor or blender; process until smooth. Add remaining milk, brown sugar, eggs, cinnamon, ginger and salt; process until well blended. Pour into 6 inch to 7 inch ( 1 1/2 quart ) soufflé dish or round baking dish that fits inside Instant Pot®. Cover dish tightly with foil.