Preheat oven to 350°F and prepare a loaf pan.
In a bowl, whisk together flour, baking powder, baking soda, and salt.
In a separate bowl, whisk together eggs, sugar, lemon juice, lemon zest, vanilla, sour cream, oil, and melted butter.
Add dry ingredients into wet ingredients and mix until just combined.
Pour batter into prepared loaf pan and smooth the top.
Bake for 50–55 minutes or until a toothpick inserted into the center comes out clean.
Cool in pan briefly, then transfer to a wire rack to cool completely.
For the glaze, whisk powdered sugar and lemon juice together until smooth.
Spread glaze over cooled loaf and allow it to set before slicing.