Preheat the oven to 350°F. Liberally greased the inside of a 10 to 12-cup capacity Bundt or tube pan by smearing softened butter into to every crack and surface with a pastry brush. Sprinkle a few tablespoons of flour inside and shake around to cover. Tap out the excess flour.
In a medium bowl, whisk together the all-purpose flour, baking powder, baking soda, and salt. Set aside.
Finely zest a large lemon. Add the zest (at least 1 tablespoon) and sugar to the bowl of a stand mixer. Massage the lemon zest and sugar together until very fragrant and smells of fresh lemons.
Add the butter. Using the paddle attachment, mix together until light and fluffy, 2 to 3 minutes.
Add in the eggs, one at a time, allowing each to blend into the batter before adding the next. Stop the mixer and scrape down the bowl.
Add in half of the dry ingredients. Mix on low until just combined. Add the sour cream and ¼ cup lemon juice then mix until smooth.
Add all but one to two tablespoons of the remaining dry ingredients and mix on low speed until just combined.
Toss the blueberries with the remaining tablespoons of dry ingredients. Pour the blueberries into the batter and fold to combine. Be gentle in order to not turn the batter purple.
Spoon the batter into the prepared pan. Bake for 60 to 65 minutes, or until a wooden skewer inserted into the center of the cake comes out clean or slightly moist - not raw batter.
Immediately set a timer for 20 minutes. When it goes, carefully unmold the cake from the pan. Gently loosen the edges of the cake with a flexible spatula. Place a wire rack or cake plate on the top of the cake. Using oven mitts, flip the cake upside. Give a few taps until you feel the cake loosen and remove the pan.
Allow the cake to continue to cool before adding the frosting and serving.