Preheat oven to 350°F. Line a muffin pan with 12 cupcake liners and set aside.
In a medium bowl, whisk together flour, kosher salt, baking powder, and baking soda.
In a small bowl, whisk together lemon juice and greek yogurt.
In the bowl of your stand mixer fitted with the paddle attachment, beat butter, sugar, and lemon zest on medium speed until light and fluffy, about 3 to 5 minutes.
Beat in eggs, one at a time, until combined.
Add one third of the flour mixture, followed by half the yogurt mixture. Then repeat again, ending with the remaining flour mixture until just combined. Do not overmix.
Fold in grated zucchini until evenly distributed throughout the batter.
Spoon batter evenly the 12 muffin liners and smooth the top.
Bake for about 22 to 25 minutes for regular sized muffins (or 12 to 15 minutes for mini muffins) or until the muffins are golden brown on the edges and a toothpick inserted into the center comes out with just a few crumbs.
Let cool in pan for 10 minutes, then turn out onto rack to cool completely.
Make the glaze by combining confectioners sugar and lemon juice until thick but easy to spread. Spread over top of the cooled muffins.