Adjust oven rack to middle position and pre-heat oven to 375°
Place muffin cups into the muffin pan
Whisk all dry ingredients together and set aside
In a separate bowl, whisk the yogurt, lemon juice, lemon zest and eggs until smooth
Gently fold the yogurt mixture into the dry ingredients until just combined. Fold in the melted butter. Do not overmix as that can make the muffins dense.
Using an ice cream scoop, divide the mixture evenly into the muffin cups.
Bake in oven for 20-25 minutes or until they are golden brown and a toothpick in the center comes out clean. Rotate the muffins pan 1/2 way through the baking process.
Glaze
While the muffins are baking, stir the lemon juice and sugar together in a small saucepan. Stirring until it makes a light syrup. About 3-5 minutes.
Remove baked muffins from the oven and brush the top with lemon syrup and sprinkle with coarse sugar. Let them cool for about 10 minutes before you serve.