Preheat oven to 350°F (180°C). Line a 9×5-inch (23×12 cm) loaf pan with parchment paper.
Mix wet ingredients in a large bowl: the zest from 1 medium lemon, ¼ cup lemon juice, 1 cup milk, ¾ cup sugar, ¼ cup olive oil, and 1 tablespoon vanilla extract.
Add dry ingredients: Sift in 2 cups all-purpose flour and 1 tablespoon baking powder, and 1 pinch of salt. Whisk gently until just combined.
Toss 1¾ cups blueberries with 1 tbsp flour, then fold into the batter. Pour into pan and smooth the top.
Bake for 50 minutes, or until a toothpick (avoiding blueberries) comes out clean. Cool in pan 15 minutes, then transfer to a wire rack.
Make glaze: Stir together 1 cup powdered sugar, 1 tablespoon milk, 1 tablespoon lemon juice. Drizzle over cooled cake. Slice and enjoy!