Add water, sugar, and walnuts to a saucepan, boil for 2 minutes, then remove walnuts and dry.
Whisk egg whites until foamy, then add cornstarch and mix until smooth.
Dip shrimp into batter one at a time, letting excess drip off.
Heat oil to 350°F and fry shrimp in small batches for 4–5 minutes until golden.
Whisk together honey, mayonnaise, and condensed milk for the sauce.
Toss fried shrimp in sauce, top with candied walnuts and scallions, and serve immediately.
