Add the water and cream to a large glass bowl. Microwave for ~30s or until warm but not hot.
Add the melted butter, egg, yeast, sugar and powdered monkfruit sweetener.
Whisk everything together. Then cover with plastic wrap for ~3min or until yeast is a little foamy.
Add roughly 100g of the keto bread and pastry flour and mix well until you get a batter-like consistency.
Add the salt, nutmeg and cinnamon. Continue to mix for ~1 minute.
Slowly add the other 80g keto flour, mixing in-between.
Once your dough comes together, grease a clean surface as well as your hands.
Remove the dough from the bowl and knead it by hand for ~3-5 minutes. It will still be a little sticky. This is okay.
Form the dough into a rough ball and place into a clean, greased bowl. Turn to coat. Then cover with plastic wrap and set somewhere warm or draft-free to rise for ~2 hours (*see tips section).
After 2 hours, remove dump the dough out onto a clean greased surface. Punch it down and then roll it out with a rolling pin. You want the dough a little thinner than you'd want your final donuts because they will puff up more with the final rise and frying.
Use a cookie cutter to cut circles out of the dough, then use a smaller cutter or the wide-end of a large piping bag tip to cut middles out of your circles (you want the middle hole a little bigger than you'd think because a again, it will shrink up as the donut rises more). Re-roll scrap dough to make more donuts.
Place the donuts and donut holes onto a parchment-lined baking sheet and cover with plastic wrap to rise for another ~45min - 1 hour.
Meanwhile, heat ~2 1/2 cups of vegetable or coconut oil in a large pot over low-medium heat. Use a thermometer and aim to get your oil in the range of 325-350*F. (I find mine fry best at 325*F). If you don't have a thermometer, do a test donut. It should take ~30s to fry each side. They should come out a nice golden brown. If they fry dark brown too quickly, your oil is likely too hot. If they don't sizzle and begin frying in the first 5-10s then your oil is likely too cold.
Fry each donut for ~30s or so per side, remove using a slotted spoon and place onto a plate lined with paper towel to soak up excess oil. Repeat for all of the donuts and donut holes.
To make the glaze, whisk all of the ingredients together in a small bowl. Dip each donut into the glaze on both sides, then place onto a plate for the glaze to set. Enjoy your Keto Sour Cream Glazed Donuts!