In a medium bowl combine sourdough, egg, and 1 tablespoon oil.
Add sugar, spices, baking powder, baking soda, salt and 1 ¾ cup flour and stir just to combine. Do not over mix! You want a soft dough that you can roll out and cut, add more flour as needed, mixing as little as possible.
Roll out dough to about ½ inch and cut with a donut cutter (or a biscuit cutter or a glass, and cut the center with a knife).
Put donuts on a baking sheet to rise for about 60-90 minutes. To speed it up, preheat your oven to the lowest setting then turn it off and place the donuts in the warm oven.To prepare ahead: let the donuts rise for 60 minutes then refrigerate. Remove from the fridge to let warm up while the frying oil is heating.
If you do not have a deep fat fryer, add 1-2 quart oil to a large Dutch oven or other pot with at least 3 inch sides. Oil should be at least an inch high. Heat the frying oil to 375℉.
Cover a plate with paper towels and have it next to the stove (or fryer). Fry donuts a few at a time until golden, about 2-3 minutes a side. Remove from the oil and place on the paper towel to drain then move to a cooling rack or plate to add toppings (if desired).
Notes
You can serve these as is or top the donuts with one of the following
powdered sugar
granulated sugar
granulated sugar mixed with gingerbread spice (4 parts sugar to 1 part gingerbread spice, for example ½ cup sugar to 1 tablespoon spice)
simple glaze: thin powdered sugar with a enough milk to make a glaze (½ cup powdered sugar start with 1 tablespoon milk and adjust as needed)
gingerbread spice glaze: same as simple glaze but add gingerbread spice