Marinade the chicken fillets in the milk, eggs, 1 tbsp salt, and 1 tbsp powdered sugar.
In a separate bowl, mix the all-purpose flour, cornflour, 1 tbsp powdered sugar, 1 tbsp paprika, 1 tbsp salt, and ½ tbsp white pepper for the flour mix.
For the sauce, combine the mayonnaise, BBQ sauce, honey, and yellow mustard.
