Preheat the oven to 180c (350f) and prepare a 12x5-inch loaf pan with parchment paper.
In a big mixing bowl, add the room temperature butter, sugar, lemon zest, vanilla extract, kosher salt, and mix with an electric hand mixer until it's creamy.
Add the sour cream (or greek yogurt), eggs, lemon juice, and mix until the mixture is well combined.
Add ½ of the milk, ½ of the flour, and baking powder, and mix it until almost combined.
Add the other half of the flour and milk and mix until just combined.
Pour the cake batter into the prepared loaf pan and spread it with an offset spatula. Bake in a 180c (350f) oven for about 55-65 minutes (depending on the oven) or until a toothpick inserted into the cake comes out clean.
Make the lemon glaze:
In a medium-sized mixing bowl, add the powder sugar, lemon juice, kosher salt, and melted butter. Mix with a spoon or a mini whisk until the mixture is smooth and silky.
Top the cake with the glaze and let it sit for a few minutes before serving. Enjoy!
Notes
Use room temperature ingredients. It is important that you use room-temperature ingredients like eggs and butter. This step ensures that your mixture mixes into a homogenous mixture and bakes perfectly.
Measure your flour correctly! When measuring your flour, avoid scooping it with a measuring cup. Instead, stir the flour with a spoon to create as many air pockets as possible, and spoon it into your measuring cup. Finally, level it with a back of a knife.
Don’t overmix the batter, you don’t want to develop the gluten in the flour. This step ensures you have a moist cake and not a dense and dry cake.
Scrape down the sides and the bottom of the bowl frequently to ensure that you have a homogeneous mixture that has unmixed parts of the mixture.
Use fresh lemon juice. The key to a great lemon cake is the use of fresh, tart lemon juice. Avoid using bottled or concentrated lemon juice, as it can lack the depth of flavor you're looking for.
Use fresh, high-quality ingredients. Opt for plump, juicy lemons and pure vanilla extract for maximum flavor. Invest in a good-quality poppy seeds to ensure a satisfying crunch in every bite.
Line your baking pan with parchment paper! This step helps the cake to bake evenly, and it makes sure that your loaf cake will release easily from the pan.
Make sure that your butter is at room temperature. An hour or two before making these cookies, take the butter out of the fridge and let it come to room temperature. The butter should be soft to the touch. If your butter is too cold, it will be harder to mix and there will be lumps of butter in the dough.
Be patient!I know it’s extremely tempting to glaze this cake as it is pulled out of the oven, but let the cake cool for at least 1 hour so it will be more firm and won’t crumble up.