oil for frying, choose a neutral tasting oil with a high smoke point like avocado or canola
Instructions
Place the flour, sugar, yeast, salt and lemon zest in the bowl of a stand mixer and stir to combine. Add the eggs, butter, vanilla extract, and milk.With the dough hook attached, knead the dough for about 10 minutes or until it's no longer sticky but is soft and supple. Add more milk or flour as needed.Form the dough into a ball, spray the bowl with oil, and place the dough ball back in the bowl. Cover the bowl loosely with plastic wrap and let it rise in a warm place for 45-60 minutes or until doubled in size.
Punch down the dough in the center. Divide the dough into uniform pieces. I like to weigh the dough to get themas close to equal as reasonably possible. At about 80 grams per piece you'll get 15 Berliner donuts.Using the palms of your hands, roll the dough pieces into balls and place them on a lined baking sheet, keeping space between them to allow them room to rise. Cover them with a clean towel or cover loosely with plastic wrap and let them rise in a warm place for another 30-60 minutes or until nearly doubled in size and nice and puffy.Make sure to give the dough balls adequate time to rise as this will be crucial for achieving the right texture.
Heat the oil in a deep pan. The oil should be at least 2 inches deep. Keep the temperature between 350-365 F. If it's not hot enough the donuts will soak up the oil and be greasy. If the oil is too hot the outside will burn before the inside is fully cooked. I like to keep it at just over 350 F.Working in batches, carefully lower a few of the dough balls into the hot oil. The temperature should be such that the Berliner will cook for on each side for about 2 minutes or slightly less. After about 2 minutes, or when the bottom is a deep golden brown, carefully flip the donuts over and continue to cook for about another 2 minutes or until deep golden brown.Do not at any point submerge the Berliner under the oil otherwise they will not develop the white rim around the center that is characteristic of Berliner. Remove the Berliner and place them on paper towels to drain. Repeat the process for the remaining donuts.
Once the Berliner are cool enough to handle, it's time fo fill them.Place the jam in a piping bag fitted with a filling tip. Push the filling tip into the side ofBerliner, along the white rim, and squeeze some jam into the donut. Repeat this for all of the donuts. Place the granulated sugar into a wide shallow bowl and mix in just a touch of cinnamon. Place a donut on the sugar, scoop some sugar on top of it, and roll it around in the sugar until well coated. Repeat for all remaining donuts.Place the sugar coated donuts on a wire rack and dust the tops with powdered sugar.Berliner donuts are best eaten while still a little warm and definitely on the same day, but will keep for a couple of days in an airtight container at room temperature.