Mix lupin flour (or fat-reduced almond flour), almond flour, sweetener, baking powder and xanthan gum in a small bowl. Set aside.
Whisk thoroughly together in a medium bowl the eggs and vanilla extract. Whisk in the dry ingredients followed by the heavy cream and water, a tablespoon at a time. You can play with the thickness a bit, but I found the best consistency to be with 6 TBSP of water (the batter is thicker, but will fluff up nicely in the oil). Mix in the mozzarella and allow the batter to rest while you heat up your oil.
Prepare your frying station by adding enough oil to make it roughly 1-inch deep, and heat it up to 350°F/180°C. Transfer the batter to a piping bag (or ziplock!) and cut out the tip (1cm or 1/3" wide).
Pipe into oil in a circular motion and fry until deep golden, flipping it over gently to get both sides. Serve right away with powdered 'sugar'!
*To whip up killer keto funnel cakes you’ll need either lupin flour or the fat-reduced almond flour! My one suggestion is that you stick to this brand for the time being… as others I’ve tried actually leave a bitter aftertaste! And you may also want to avoid it if you’re allergic to peanuts. (See section on flours for more deets).Fun fact: Alton Brown (you know, chef extraordinaire!) actually suggests using choux pastry for funnel cakes! So technically you can also make our keto churros as ‘funnel cakes’ in case you don’t have some of these ‘newer’ grain free flours.**The mozzarella cheese provides that wonderful crispness that grain free flours lack to achieve. I’ll also add that this is why the recipe has no added salt! You cannot taste it (at all!) as long as you use a neutral flavored cheese (the mozzarella cheese from Organic Valley is a bit bland and so perfect for this task lol!). Please note that nutrition facts were estimated for the batter only (so expect the calorie and fat macros to be higher to take into account the fried oil... but carbs will remain the same!).