Preheat oven to 425. Line 6 wells in a jumbo muffin tin. Set aside.
In a large bowl or bowl of a stand mixer and mix together the zest and sugar until well mixed and fragrant.
In a second bowl, whisk together the dry ingredients. Add them to the sugar mixture in a steam as the mixer runs. A clumpy dough will form.
Add the oil, juice, eggs, buttermilk and extracts. Mix until a fairly smooth batter forms. Stir in the poppy seeds.
Fill each well about 3/4 of the way. Sprinkle with coarse sugar if using.
Bake for 5 minutes then reduce heat to 375 and bake an additional 20 minutes or until a toothpick inserted in the center of a muffin comes out clean or with one or two coarse crumbs.
Meanwhile, whisk together glaze ingredients, if using.
Remove to wire rack and drizzle with glaze if using. Or leave the muffins unadorned all together!
Cool on wire rack.