Preheat the oven to 350ºF.

In a large bowl, mix sugar and lemon zest with your fingers, releasing all the oils from the zest. Then add all other dry ingredients with a whisk to mix thoroughly.

Combine the wet ingredients in a small sauce pan over medium-low heat and mix until the margarine is just melted. This mixture should be just slightly warm to the touch.

Add the wet mixture to the dry and mix until just combined. It should form a very soft dough.

Using a tablespoon or a piping bag, transfer dough into a slightly greased nonstick doughnut pan. Smooth out the top of each dough with your fingers.

Bake for 12 minutes. They should not be browned on top, but a toothpick will come out clean.

Invert the hot pan over a cutting board or cooling rack to release the doughnuts. Allow to cool completely before decorating.

For the Glaze:

Combine the glaze ingredients in a medium saucepan over low heat. Whisk until the glaze is smooth. Remove from heat and immediately begin dunking the donuts, one by one, into the lemon glaze.