Preheat oven to 325°F and generously grease and flour a 10” bundt pan.
In a medium sized bowl, whisk the flour, baking powder and salt, and set aside.
In the bowl of an electric mixer, blend together the melted butter, sugar. Add eggs, one at a time, blending for 10-15 seconds between each addition.
Add vanilla, lemon zest and lemon juice. Mix until well combined.
While slowly mixing, add about half of the flour mixture, and then add the sour cream.
Continue blending and add the remaining flour mixture, and then the milk. Stop the mixer.
In a small bowl, add the frozen blueberries and toss with 1 rounded tablespoon of flour. Stir until the berries are all evenly coated (this will help prevent the berries from all sinking to the bottom of the cake).
Add the flour coated berries to the batter, and gently but quickly stir by hand with a spatula until just combined.
Pour/scoop the batter into the prepared pan and bake for 65-80 minutes, or until the top is golden brown and a toothpick inserted into the cake comes out clean.
Allow the cake to cool in the pan for 1 hour before attempting to remove. To remove cake from pan, use a small spatula to gently loosen around the edges, then invert pan onto cake plate, or baking sheet.
Prepare the glaze by simply whisking together the melted butter, powdered sugar and lemon juice in a bowl. Allow the glaze to sit for 10 minutes or so to thicken a bit, and then pour glazed over the cake.
Slice and enjoy!