Preheat your oven to 350°F and spray your donut pan with oil or butter.
Zest and juice your lemon, and chop all the candied lemon, set aside.
Combine the flour, baking powder, and salt in a bowl and whisk to combine.
Combine the yogurt, oil, egg, lemon zest, 2 teaspoons of lemon juice, and sugar in a bowl and beat until smooth and creamy, 1 to 2 minutes.
Add the wet ingredients into the dry and fold to combine. When they're about halfway combined, add in 2 tablespoons of the chopped lemon peel and continue folding until the batter is consistent and there are no dry spots.
Using a piping bag or spoon, carefully fill the donut pan. Only fill each donut spot about halfway full.
Bake for 11 to 12 minutes. Remove from oven and let cool in pan for 1 minute then flip onto a cooling rack, tapping lightly if necessary to release the donuts. Repeat with remaining batter.
Allow the donuts to cool completely before glazing.
When cool, combine the powdered sugar and remaining lemon juice (2 tablespoons) and whisk until it's a smooth glossy glaze.
Dip each donut in and allow the excess to drip off. Sprinkle the donuts with the remaining chopped candied lemon peel and let the glaze dry.
When dry, enjoy and store any extras on a platter loosely covered by plastic wrap at room temperature.
Notes
*I find 1 large lemon to be plenty to provide the proper amount of zest and juice for both the donuts and the glaze. You may need more than one if you have small lemons or one that isn't juicy. *One single serve cup of greek yogurt is the proper amount, or about 1/2 a cup.