Adjust the oven rack to the middle position and preheat the oven to 350 degrees. Coat a 9 inch round cake pan with coconut oil cooking spray.
Whisk together the flour, baking powder, and salt in a bowl.
Split the vanilla bean pod in half with a knife. Using the back of the knife, scrape the inside of the vanilla bean pod to remove the seeds.
Place the scraped seeds along with the 3/4 cup sugar and butter into a large mixing bowl.
Using a hand mixer, beat until pale and fluffy, about 3 minutes.
Add the whole eggs and egg white, one at a time, and beat until combined.
Beat in the lemon zest until well combined.
Slowly add the flour mixture in 3 additions, alternating with 2 additions of milk, scraping down the bowl as needing and beating with mixer until combined.
Give the batter a final stir by hand.
Gently fold in the blueberries.
Scrape the batter into the prepared pan, smooth the top, and gently tap the pan on the counter to release any air bubbles.
Sprinkle the remaining 2 tablespoons of sugar evenly over the top of the cake.
Place into the oven and bake until the top is lightly golden and a wooden skewer inserted into the center of the cake comes out clean, about 35-45 minutes, rotating pan halfway through baking.
Let the cake cool in the pan for at least 30 minutes.
Make the whipped cream.
Pour the ice-cold heavy whipping cream in an ice-cold large bowl.
Add the powdered sugar, lemon zest, lemon juice, and vanilla.
Beat with a hand mixer on medium-low until foamy, about 1 minute.
Increase speed to high and beat until soft peaks form, 2-3 minutes.
Slice the cake and top with the lemon whipped cream. Serve and enjoy.