Preheat your oven to 350 degrees. In a small sauce pan on low heat, melt your butter for your loaf.
In a large bowl whisk together your milk, sugar, lemon zest, lemon juice, melted butter, vanilla, and egg until well combined.
In the bowl of wet ingredients, add in your flour, baking powder, and salt. Stir just until combined - don’t over mix because it will make your loaf more dense.
In a small bowl add your fresh and frozen blueberries and toss in the 2 tbsp of all-purpose flour.
Fold the blueberries into your batter very gently with a spatula.
Grease your loaf pan well to avoid sticking. Pour your batter into the pan and cook on the center rack for 65 minutes.
While loaf is cooking - make your glaze by combining the powdered sugar, vanilla, milk, and melted butter to a small bowl and whisk to combine. Set in fridge while loaf finishes cooking.
Use a toothpick to test doneness of your loaf. Your toothpick should come out clean.
Let cool for 30 minutes, scrape the sides with a knife to get out. Remove loaf carefully and set on parchment paper. Drizzle with your icing. Slice and serve! Enjoy!