Preheat the oven to 350°F. Grease a 9 x 5 inch loaf pan and line with a parchment sling for easy removal.
In a large bowl, whisk together the flour, baking powder, salt, and poppy seeds.
In a medium bowl, whisk the eggs and granulated sugar until slightly frothy. Whisk in melted butter, sour cream, milk, lemon juice, vanilla, and almond extract until smooth.
Add the lemon zest to the wet mixture and stir to combine.
Pour the wet ingredients into the dry ingredients and fold gently until just combined and no dry pockets remain. Do not overmix.
Transfer batter to the prepared pan, smooth the top, and tap the pan once to release air bubbles.
Bake for 50 to 60 minutes, or until a toothpick inserted in the center comes out clean or with a few moist crumbs. Tent loosely with foil if browning too quickly.
Cool in the pan for 10 minutes, then lift out and cool completely on a wire rack.
For the glaze: whisk powdered sugar with lemon juice and milk until smooth and pourable. Adjust with a few drops more milk if needed. Stir in lemon zest if using.
Drizzle glaze over the cooled loaf. Let set for 10 minutes, then slice and serve.
Notes
For extra lemon flavor, brush the warm loaf with 1.0 tbsp lemon juice mixed with 1.0 tbsp sugar before glazing. Store airtight at room temperature for up to 3 days or refrigerate for up to 1 week. Freezes well (without glaze) for up to 2 months.