1/2cupnonfat plain Greek yogurt - at room temperature
1/4cupnonfat milk - at room temperature
3tablespoonsunsalted butter - melted and cooled (or substitute melted, cooled coconut oil, canola oil, or very light olive oil)
1 1/2teaspoonspure vanilla extract
1/4teaspoonpure almond extract
FOR THE GLAZE:
2tablespoonsbutter - softened
1 1/4cupspowdered sugar
1/2teaspoonpure vanilla extract
1-2tablespoonsorange juice - reserved from the oranges above
Preheat the oven to 375 degrees F. Lightly coat a 12-cup muffin tin with cooking spray or line with paper liners. Place the sugar in a medium mixing bowl, then zest both oranges directly into it. Rub together the sugar and orange zest with your fingers, until the sugar is fragrant, moist, and light orange throughout. Stir in the flour, poppy seeds, baking soda, and salt. Juice the zested oranges and set aside 1/3 cup plus 1 tablespoon for the muffins and 2 tablespoons for the glaze.
In a separate bowl, whisk together the eggs, Greek yogurt, milk, butter, vanilla extract, almond extract, and 1/3 cup plus 1 tablespoon orange juice. (All of these ingredients do need to be as close to room temperature as possible, or the butter will resolidify. If you don't have time to wait, use canola oil or a very light tasting olive oil, which will stay liquid.) Add the wet ingredients to the dry ingredients and mix gently by hand, just until combined. Do not overmix.
Divide the batter among the 12 muffin cups, filling three-quarters of the way to the top (I like to use a big cookie scoop for the tallest, fluffiest muffins). Bake 12-14 minutes, until the tops are dry and spring back lightly when touched and a toothpick inserted in the center comes out clean. The muffins will look a little flat but will still be perfectly moist and delicious. Let cool 3 minutes in the pan, then gently transfer to a wire rack to cool completely.
For the glaze, melt the butter in a small saucepan or in the microwave in a microwave-safe bowl. Whisk in the powdered sugar, vanilla, and 1 tablespoon orange juice. Continue adding juice, 1 teaspoon at a time, until your desired consistency is reached. Drizzle over the top of the muffins. Enjoy warm or cooled.