In a medium-size mixing bowl, mix three cups of confectioner’s sugar and one-half teaspoon of lemon zest together. Stir in one-half cup of lemon juice as needed until you reach a glaze-like consistency.Set aside until you are ready to use.
I prefer to use a stand mixer for this recipe. I find it easier to mix in the five cups of Bisquick.
In the bowl of your mixer, add one and one-quarter cups of white sugar, six large egg yolks, two tablespoons of unsalted butter, and one tablespoon of lemon zest. Mix for approximately three minutes or until well combined.
Add one and one-half cups of sour cream mixing again for another three minutes.
In a separate bowl sift together one tablespoon of baking powder, one teaspoon of salt, and five cups of Bisquick.
Add the dry ingredients into the wet ingredients and mix on slow until incorporated. Do not over-mix.
Refrigerate the dough in a parchment-lined covered bowl for at least one hour.
Lay the dough on a lightly floured surface using Bisquick. Roll out the dough with a rolling pin, dusting the dough with Bisquick as needed. Roll out to a thickness of approximately one-half inch.
Use a round cutter to cut the donut shapes and place them on a parchment-lined baking sheet.
Heat frying oil to 340 degrees Fahrenheit.
Lower the donuts into the oil, cooking until each side becomes golden brown. This usually takes one and a half to two minutes for each side.
Remove the donuts from the oil and let cool on a paper towel.
While the donuts are warm, dip the tops into the glaze.