Add orange zest, allulose, orange juice (or just someplain water, seriously no biggie!), white wine vinegar, coconut aminos, ginger, garlic, and molasses (again, optional) to a medium saucepan and heat up over medium/low heat. Once it begins to simmer, make a slurry with your arrowroot (i.e. mix it with a little cold water before adding it in so it doesn't clump up!), and whisk it into your orange sauce. Allow it to simmer until it thickens up nicely, remove from heat and set aside while you prepare yor chicken.
Make the chicken
Prepare your frying station by adding enough oil to a dutch oven (or pot) to make it about 2-inch deep. You can save a lot of oil by using a narrower pan and frying in batches. Heat up oil over low heat while you batter the chicken.
Mix the whey protein, arrowroot (optional), baking powder, xanthan gum and salt in a shallow plate or dish. In a second plate or dish, whisk the egg with cream and vinegar.
Coat the chicken by dipping in the egg mix, followed by the whey protein mix, and immediately frying in the hot oil (350F to be precise) for 2-3 minutes until golden (and if you have a thermometer around, internal temp should read 165F). You want to work in batches small enough so that they're not overcrowded.
Toss the chicken in the orange sauce and serve right away over a bed of cauliflower rice.
Notes
*Since most of the flavor for your orange sauce comes from the orange zest itself (yes, seriously!), you really can leave out the orange juice completely (and save yourself 3g net carbs). But if your macros allow, it does make it a tad bit better.
For the keto fried chicken 'batter'
We're doing something very similar here (if not near identical) as the batter for my fish tacos and fish 'n chips. But I've heard back from you guys that unless you fry in a generous amount of oil, the whey protein isolate batter essentially just sticks to the pan (though I suppose this would happen with any type of batter right?). Still, I hear ya- we needed to make the batter a little sturdier. Adding a touch of xanthan gum helps so (so!) much for that, as does adding a tablespoon (or four, lol) of arrowroot starch. Though *really* keep in mind that adding the latter will increase your carb count, possibly taking your orange chicken more into the low carb and paleo territory depending on how much you add (per usual, you do you!). Having said that, given that the whey isolate batter is essentially carbless... you do have a little wiggle room here. Just a thought, as adding just a tablespoon of arrowroot does improve the texture quite a bit and adds just 3g net carbs a serving. Oh and while we're in the subject of possibly adding some carbs, I've always noticed 'asian inspired' keto dishes benefit greatly from a touch of blackstrap molasses as its one of those ingredients that packs a whole load of punch (i.e. you know, the famous umami)(and p.s. I'm talking about 1/4 of a teaspoon, so the carb increase is really negligible per serving)(p.s. 2 I didn't have any on hand here, otherwise my sauce would've come out darker... and even a tad bit better). Still, totally optional and one of those 'if you have on hand it would be great' sorta thing.