Note: you will need approximately 4 cups of oil to fry the donuts, but the amount will differ based on the size of your dutch oven or whatever you are using to fry them. You want at least 3-4" of depth. You can use peanut, canola, or vegetable oil.
Place a cooling rack over a baking tray and set aside.
Place your frying oil in a dutch oven over medium heat. Use a candy thermometer to ensure you bring the oil to 350F.
Cut out the center of each biscuit and then stretch the biscuit a bit to make the hole and biscuit donut wider - approximately by 1/2".
Once the oil is hot, fry each donut individually for about 1 minute per side, until golden brown.
Set each fried donut on the cooling rack to allow excess oil to drip off.
Once all donuts have been fried, turn off the heat for the oil.
Sift the powdered sugar into a large bowl.
Whisk in the lemon juice and most of the zest from 1 lemon.
Dip each donut into the lemon glaze, then place it back on the cooling rack.
If desired, garnish with additional lemon zest.
Allow to sit until glaze is set, about 30 minutes.
