Preheat the oven to 350° F. Line a 9×5 inch loaf-pan with parchment paper. Set aside.
In a large bowl, combine the granulated sugar and lemon zest. Using your fingertips, rub the ingredients together. This will help bring out the oils in the zest, adding more flavor. To the sugar mixture, add the melted butter and mix well. Add the eggs one at a time, then continue with the milk, lemon juice, yogurt or sour cream, and vanilla. Slowly add flour, baking powder, poppy seeds, and salt. Mix until combined.
Pour batter into the prepared loaf-pan. Bake for 45-60 minutes, or until a toothpick inserted into the center comes out mostly clean. Let cool completely before adding the glaze.
Meanwhile, make the lemon glaze. In a medium bowl, combine powdered sugar, lemon juice, cream or milk, and salt. If the glaze seems too thick, add an additional teaspoon of cream or milk.
Once the loaf is cool, remove from the pan and pour the glaze all over the top, allowing it to drip down the sides. Let the glaze sit for a few minutes to set before slicing. Enjoy!
