Preheat oven to 350°F and lightly oil an 12 cavity doughnut pan, or a couple of 6 cavity pans.
Whisk together the flour, sugar, baking powder, baking soda, and salt in a large mixing bowl.
In a small container, such as a liquid measuring cup, stir together the milk, lemon juice, oil, lemon zest, lemon extract, and yellow food coloring, if you're using it.
Pour the milk mixture into the bowl with the dry ingredients, and stir the ingredients together just until they're completely combined. Don't overmix the batter.
Divide the batter among the doughnut cavities, filling each one to a level just barely below the rim. You can spoon the batter in, or pipe it using a pastry bag if you'd like.
Bake the doughnuts for 12 minutes, or until they're puffy and ever so slightly browned around the edges.
Place the pans on a cooling rack and let the doughnuts cool completely.
Once the doughnuts are cool, stir the glaze ingredients together in a small bowl. You can add extra powdered sugar if if seems too thin, or more lemon juice or some water if if seems too thick.
Dip the top of each doughnut in the glaze, then place it on a sheet of parchment paper until the glaze has set,
Serve.