First, preheat your oven to 375°F (190°C) and line a 12-cup muffin tin with paper liners.
In a medium bowl, whisk together the flour, salt, baking powder, and baking soda. Set this aside for now.
In a separate, larger bowl, whisk together the Greek yogurt (or sour cream) and the 2 tablespoons of fresh lemon juice.
Now, grab your softened butter and granulated sugar. In a stand mixer with the paddle attachment, or using a hand mixer and a large bowl, cream the butter and sugar together on medium speed until they are light and fluffy (about 2-3 minutes).
Add the lemon zest to the creamed butter and sugar and mix for about 30 seconds until fragrant.
Beat in the eggs one at a time, mixing well after each addition. Scrape down the sides of the bowl as needed.
Reduce the mixer speed to low. Add about half of the dry ingredients to the wet ingredients and mix just until combined.
Next, add the yogurt/lemon juice mixture and mix until just incorporated.
Add the remaining dry ingredients and mix on low speed just until the batter is combined and there are no visible streaks of flour. Be careful not to overmix!
Gently fold in the drained grated zucchini using a spatula. Don't mash it in, just fold until it's evenly distributed.
Divide the batter evenly among the 12 prepared muffin cups, filling them about two-thirds to three-quarters full.
Bake for 20-25 minutes, or until a toothpick inserted into the center of a muffin comes out clean.
Let the muffins cool in the tin for 5-10 minutes before transferring them to a wire rack to cool completely.
While the muffins cool, make the glaze! In a small bowl, whisk together the powdered sugar and 1 ½ tablespoons of fresh lemon juice. Add more lemon juice, about ½ teaspoon at a time, if needed for desired consistency.
Once the muffins are completely cool, drizzle the glaze over the tops. Let the glaze set for a few minutes before serving.