Preheat oven to 350*.
Line a loaf pan with parchment paper.
In a large bowl with a mixer, blend together melted butter, sugar, eggs, vanilla, lemon zest and lemon juice until well combined.
Slowly add in flour, baking powder and salt.
Rinse the blueberries so they are a little bit wet, and mix with 1 Tablespoon of flour. (The flour helps them not sink to bottom of loaf).
Add the berries to the batter and gently stir in with a spoon (don't use electric mixer, it will break the blueberries)
Pour batter into prepared loaf pan(s)
Bake for 55-65 minutes for large loaf. 40-50 minutes for smaller loaves.
Let bread cool in the pan for 30 minutes and then move to a wire rack.
Prepare glaze by whisking the melted butter, powdered sugar, lemon juice and vanilla extract and whisk until smooth.
Pour over the loaf and let sit for a few minutes before serving.