In a large mixing bowl, combine 2 cups of all-purpose flour, 3/4 cup of granulated sugar, 1 tablespoon of baking powder, 1/2 teaspoon of baking soda, and 1/2 teaspoon of salt. Whisk these dry ingredients together until well blended.

In a separate bowl, whisk together 2 large eggs, 1 cup of buttermilk, 1/3 cup of vegetable oil, the zest of 3 oranges, and 1/2 cup of fresh squeezed orange juice until smooth and well combined.

Gradually add the dry ingredient mixture to the wet ingredients. Gently fold everything together until just combined.

Cover the bowl with a clean kitchen towel and let the batter rest for about 15 minutes.

While the batter rests, line a 12-count muffin pan with 6 liners, filling every other well.

After resting, spoon the thick batter into the muffin liners, filling them to the top. Bake at 425°F for 7 minutes, then lower to 350°F for an additional 13-16 minutes.

Once baked, remove from the oven and let cool in the pan for 5 minutes, then transfer to a wire rack. To make the glaze, mix 1 cup of powdered sugar with orange juice to the desired consistency and drizzle over the cooled muffins.