Preheat the oven to 425˚F (218˚C). Lightly grease a mini donut pan.

In a small bowl, mix the sugar and lemon zests together. Add brown sugar and set aside.

In a large mixing bowl, beat the butter for 2 minutes. Add lemon sugars and vegetable oil, then beat until fluffy, about 3 minutes. Add egg and beat to combine.

Stir in the baking powder, baking soda, salt, and vanilla. Mix well.

Alternate adding the flour and milk to the butter mixture in 3 additions, starting and finishing with the flour. Mix until just combined.

Spoon the batter into a piping bag and fill the donut pan all the way to the rim.

Bake for about 6 – 8 minutes, testing with a toothpick for doneness. The toothpick should come out clean.

Cool in the pan for 5 minutes, then transfer the donuts to a cooling rack to cool completely.

For the glaze, combine powdered sugar, milk, 1½ tablespoons lemon juice, and pink food coloring (if using) in a medium bowl. Whisk until smooth, adding more lemon juice if too thick.

Glaze the donuts and let them set for 20 minutes.