Pour oil into a medium-sized pot or saucepan and heat over medium heat while you prepare the fritter dough.
To a large bowl whisk together flour, sugar, baking powder, cinnamon and salt. Add frozen or fresh berries and fluff together with a fork. Set aside.
To a smaller bowl, add the sourdough starter or discard, egg, milk, melted butter and vanilla extract. Whisk together until completely combined.
Pour the liquid mixture on top of the flour/berry mixture and mix together until just combined.
Before frying the fritters, check the temperature of the oil. The optimal temperature is about 350ºF that can be checked with a thermometer. You may need to adjust the temperature of your stove if the oil is too hot or too cool.
Scoop the fritters using a 2 Tablespoon cookie scoop or a kitchen spoon and carefully release into the hot oil. Repeat with enough fritters to mostly fill the pot and fry for about 2-3 minutes total until crips on the outside and light and tender in the middle.
Remove from the pot with a slotted spoon, letting the oil drip off and place on a baking rack where the oil will continue to drain off the fritters. Finish frying the remaining fritter batter.
Mix up a quick glaze, whisking together the powdered sugar, milk and vanilla extract. Add a pinch of salt if desired. Drizzle over the fritters and enjoy warm!
